BOSTON (WHDH) -- James ‘Whitey’ Bulger claims the government granted him immunity - and former Massachusetts Governor William Weld said that he can't deny that claim.

Bulger is accused of committing 19 murders but the 83-year-old said that while he was working as an informant for the FBI, the late federal prosecutor Jeremiah O'Sullivan gave him immunity.

According to the Herald, Weld, a former U.S. attorney said he had never heard of an immunity deal.

But the former governor also said he's unable to promise that no such deal ever existed.

Bulger is set to go on trial in June.