In 2010 the sixth President of Iran Mahmoud Ahmadinejad offered 3 points explaining who was responsible for the 9/11 attacks at the United Nations.
In point number 2 he suggests that some corrupt element withing the USA government was responsible.
According to some Western media, weeks later he stated that the 9/11 attacks were a big lie.
Also Lawyers Committee for 9/11 Inquiry and AE911Truth which is an organization endorsed by 3000 architects a engineers who demand a new investigation. Also this view is endorsed by Iranian media such us Manoto TV and Russian media such us Russia Today.
Could an international tribunal or the United Nations suphoena members of the former USA goverment because of 9/11? For example people like Dick Cheney, Donald Rumsfeld or even former President George W. Bush.