A man who claimed to spy on mosques for the FBI provided the agency with valuable information for a federal prosecution, a court transcript showed on Friday.

The transcript from an August 2007 hearing states that Craig Monteilh provided "very, very valuable" information to the FBI, which prompted a deputy district attorney to ask a Superior Court judge to have his probation terminated in an unrelated theft case.

The transcript released on Friday does not state the nature of the information nor the relationship the FBI had with Monteilh, who has accused the agency of failing to properly pay him for his work as an informant.

The 47-year old fitness consultant from Irvine claims he infiltrated Orange County mosques in 2006 and 2007 for an anti-terrorism task force — an activity that caused an uproar in Muslim communities.

Monteilh claims he helped the FBI glean information about Ahmadullah Niazi, the brother-in-law of Osama bin Laden's bodyguard who has been charged with lying about terrorist ties on his passport and citizenship papers. Niazi has pleaded not guilty.

Monteilh spoke out about his experiences after an FBI agent testified in Niazi's case that the agency used an informant that Niazi had reported to authorities for talking about terrorism. While the agent did not mention Monteilh by name, police records show Niazi helped an Irvine mosque obtain a court order against Monteilh in 2007.

On Friday, Monteilh said the recently released court transcript helps bolster his case against the FBI. The transcript was unsealed by a West Covina judge on Thursday at Monteilh's request.

Monteilh has filed a claim alleging the FBI failed to pay him $100,000 and let him go to prison for eight months for work he claims was related to an agency task.

The FBI does not confirm nor deny the identity of its informants, the agency said in a statement.