tldr; the agreement is a mess, one-sided, do not sign.

This agreement does little to serve your interests, and a lot to harm them.

It is also fairly poorly phrased, I have doubts that someone with legal knowledge wrote it. It states:

I agree to not disclose, or discuss with anyone, any matters relating to the investigation

You are agreeing not to talk to the investigator. If you do talk to them, you will be in breach of the terms you've agreed to. I'm sure they'll just say "oh, that's not what it means" - but that is not how contracts work, they mean what they say.

It also says:

which includes but is not limited to: ... All documents created by me or shared with me during the investigation.

This applies to documents created during the investigation, not in relation to the investigation, not for use in the investigation, not related to the complaint. And again, you can't share these documents with anyone, including the investigator.

It may well be unenforceable, as it gives you nothing in exchange for the rights you are giving up, and the concept of "consideration" is key to the common law of contracts in the USA, and also Canada (stemming from British common law) which means both parties must receive something of value:

Here's a wiki article on Consideration in US law

and a page on Consideration in Canadian law

With all of these flaws and the fact that it may well be unenforceable, it would not be wise to sign it.

If it did the following, it might be a more useful agreement:

1. Had time limits, after which the restrictions are lifted
2. Allowed you to acknowledge the case and state that you can't discuss it while it is ongoing
3. Applied only to the workplace, talking to the press and publishing details to the public internet, such as social media - this may already be in your contract of employment (relating to bringing the company into disrepute) if so it isn't really a restriction being applied by this agreement, but a re-iteration of the existing agreement
4. Promised a fair investigation in a timely manner, with a report at the end, and appropriate action is taken if claims are substantiated, and libel has occurred

Or, they could offer you money right now for your silence, that would absolutely be consideration, as long as the sum could be considered reasonable ($1 would probably not cut it). There are also cases where NDAs turn out to be invalid:

11 ways NDAs can be invalidated

An actual case where an NDA was found to be too broad

tldr; the agreement is a mess, one-sided, do not sign.

This agreement does little to serve your interests, and a lot to harm them.

It is also fairly poorly phrased, I have doubts that someone with legal knowledge wrote it. It states:

I agree to not disclose, or discuss with anyone, any matters relating to the investigation

You are agreeing not to talk to the investigator. If you do talk to them, you will be in breach of the terms you've agreed to. I'm sure they'll just say "oh, that's not what it means" - but that is not how contracts work, they mean what they say.

It also says:

which includes but is not limited to: ... All documents created by me or shared with me during the investigation.

This applies to documents created during the investigation, not in relation to the investigation, not for use in the investigation, not related to the complaint. And again, you can't share these documents with anyone, including the investigator.

It may well be unenforceable, as it gives you nothing in exchange for the rights you are giving up, and the concept of "consideration" is key to the common law of contracts in the USA, and also Canada (stemming from British common law) which means both parties must receive something of value:

Here's a wiki article on Consideration in US law

and a page on Consideration in Canadian law

With all of these flaws and the fact that it may well be unenforceable, it would not be wise to sign it.

If it did the following, it might be a more useful agreement:

1. Had time limits, after which the restrictions are lifted
2. Allowed you to acknowledge the case and state that you can't discuss it while it is ongoing
3. Applied only to the workplace, talking to the press and publishing details to the public internet, such as social media - this may already be in your contract of employment (relating to bringing the company into disrepute) if so it isn't really a restriction being applied by this agreement, but a re-iteration of the existing agreement
4. Promised a fair investigation in a timely manner, with a report at the end, and appropriate action is taken if claims are substantiated, and libel has occurred

Or, they could offer you money right now for your silence, that would absolutely be consideration, in some jurisdictions, the sum may need to be considered reasonable, but this is not universal. 

There are also cases where NDAs turn out to be invalid:

11 ways NDAs can be invalidated

An actual case where an NDA was found to be too broad

tldr; the agreement is a mess, one-sided, do not sign.

This agreement does little to serve your interests, and a lot to harm them.

It is also fairly poorly phrased, I have doubts that someone with legal knowledge wrote it. It states:

I agree to not disclose, or discuss with anyone, any matters relating to the investigation

You are agreeing not to talk to the investigator. If you do talk to them, you will be in breach of the terms you've agreed to. I'm sure they'll just say "oh, that's not what it means" - but that is not how contracts work, they mean what they say.

It also says:

which includes but is not limited to: ... All documents created by me or shared with me during the investigation.

This applies to documents created during the investigation, not in relation to the investigation, not for use in the investigation, not related to the complaint. And again, you can't share these documents with anyone, including the investigator.

It may well be unenforceable, as it gives you nothing in exchange for the rights you are giving up, and the concept of "consideration" is key to the common law of contracts in the USA (stemming from British common law) which means both parties must receive something of value:

Here's a wiki article on Consideration in US law

and a page on Consideration in Canadian law

With all of these flaws and the fact that it may well be unenforceable, it would not be wise to sign it.

If it did the following, it might be a more useful agreement:

1. Had time limits, after which the restrictions are lifted
2. Allowed you to acknowledge the case and state that you can't discuss it while it is ongoing
3. Applied only to the workplace, talking to the press and publishing details to the public internet, such as social media - this may already be in your contract of employment (relating to bringing the company into disrepute) if so it isn't really a restriction being applied by this agreement, but a re-iteration of the existing agreement
4. Promised a fair investigation in a timely manner, with a report at the end, and appropriate action is taken if claims are substantiated, and libel has occurred

Or, they could offer you money right now for your silence, that would absolutely be consideration, as long as the sum could be considered reasonable ($1 would probably not cut it). There are also cases where NDAs turn out to be invalid:

11 ways NDAs can be invalidated

An actual case where an NDA was found to be too broad

tldr; the agreement is a mess, one-sided, do not sign.

This agreement does little to serve your interests, and a lot to harm them.

It is also fairly poorly phrased, I have doubts that someone with legal knowledge wrote it. It states:

I agree to not disclose, or discuss with anyone, any matters relating to the investigation

You are agreeing not to talk to the investigator. If you do talk to them, you will be in breach of the terms you've agreed to. I'm sure they'll just say "oh, that's not what it means" - but that is not how contracts work, they mean what they say.

It also says:

which includes but is not limited to: ... All documents created by me or shared with me during the investigation.

This applies to documents created during the investigation, not in relation to the investigation, not for use in the investigation, not related to the complaint. And again, you can't share these documents with anyone, including the investigator.

It may well be unenforceable, as it gives you nothing in exchange for the rights you are giving up, and the concept of "consideration" is key to the common law of contracts in the USA, and also Canada (stemming from British common law) which means both parties must receive something of value:

Here's a wiki article on Consideration in US law

and a page on Consideration in Canadian law

With all of these flaws and the fact that it may well be unenforceable, it would not be wise to sign it.

If it did the following, it might be a more useful agreement:

1. Had time limits, after which the restrictions are lifted
2. Allowed you to acknowledge the case and state that you can't discuss it while it is ongoing
3. Applied only to the workplace, talking to the press and publishing details to the public internet, such as social media - this may already be in your contract of employment (relating to bringing the company into disrepute) if so it isn't really a restriction being applied by this agreement, but a re-iteration of the existing agreement
4. Promised a fair investigation in a timely manner, with a report at the end, and appropriate action is taken if claims are substantiated, and libel has occurred

Or, they could offer you money right now for your silence, that would absolutely be consideration, as long as the sum could be considered reasonable ($1 would probably not cut it). There are also cases where NDAs turn out to be invalid:

11 ways NDAs can be invalidated

An actual case where an NDA was found to be too broad