WASHINGTON (Reuters) - A former Naval Criminal Investigative Service (NCIS) agent was sentenced on Friday (Oct 15) to 12 years in federal prison for leaking information to a defence contractor in exchange for cash, luxury travel and the services of prostitutes, the US Justice Department said.

John Bertrand Beliveau, 47, of York, Pennsylvania, had pleaded guilty to helping Singapore-based contractor Leonard Francis, also known as "Fat Leonard", perpetrate a fraud scheme on the United States Navy by providing information that allowed Francis to thwart a criminal fraud investigation of the company.

Ms Jessica Carmichael, one of Beliveau's attorneys, said Beliveau suffers from Post-Traumatic Stress Disorder and while she was disappointed at prosecutors' attempts to belittle his condition, she was happy with the ruling.

"We were very appreciative and happy that the judge did take into consideration his mental health concerns in giving a sentence below the government's recommendation," of 15 years, Ms Carmichael said.

The US District Judge in southern California also ordered Beliveau to pay US$20 million in restitution to the Navy. The Justice Department (DOJ) said Beliveau admitted to accessing NCIS databases for investigative reports related to Francis and providing copies to him so he could avoid criminal charges.

The DOJ also said in a statement that Beliveau admitted to covering up his involvement by deleting incriminating emails. In return, the department said, Francis gave Beliveau money and paid for luxury travel to Singapore, the Philippines and Thailand, as well as lavish dinners and prostitutes.

"John Beliveau's deceit was a devastating blow to the US Navy and ultimately the nation that he was sworn to protect," US Attorney Laura Duffy said in the statement.

In June, US Navy Rear-Admiral Robert Gilbeau pleaded guilty to a charge of lying to federal investigators, making him the highest-ranking officer to be convicted in the case. Gilbeau is awaiting sentencing.

Sixteen people, including 11 current or former US Navy officials, have been charged in the investigation, prosecutors said. Beliveau's sentencing ranks as the most severe punishment to date.

Francis pleaded guilty last year to bribery charges and is awaiting sentencing.