Argentine Olympic Committee president Julio Cassanello resigned after questions about his role in the country’s 1970s military dictatorship.

Cassanello sent a letter of resignation to the committee late Tuesday and the announcement was made public Wednesday by news agency Telam.

Human rights groups say Cassanello, mayor of a Buenos Aires suburb from 1970 to 1982, should be held responsible for the disappearance of two leftist militants during his term. Thousands of militants died during Argentina’s “dirty war” crackdown on dissent.

Cassanello said political and personal interests and a “relentless media operative” forced him out of the presidency. He denies responsibility in the disappearances.

He has faced pressure to step down since he assumed the post in 2005.