These are the Rules
By and large, the lawyer has a duty to their client and the administration of justice - they have more limited duties to others including their client's opponent.
Chapter 3 deals with confidentiality but it is almost exclusively couched in terms of the duty they owe their client. If the information you refer to is confidential business affairs of their client (which it may or may not be) then there are restrictions on when and to whom it can be disclosed.
If it isn't then Chapter 2 which requires "a duty to carry on the practice of law and discharge all responsibilities to clients, tribunals, the public and other members of the profession honourably and with integrity" may prevent disclosure.