A US admiral is set to plead guilty Thursday to lying to federal investigators in a bribery scandal that has tarnished a number of high-ranking navy officials.

Admiral Robert Gilbeau will admit to making a false statement before a federal judge in San Diego, his attorney David Benowitz told AFP.

Few admirals in the history of the navy have been convicted of a felony charge.

Gilbeau will be the highest ranking officer to be convicted in the so-called "Fat Leonard" probe linked to a Malaysian businessman.

The US Navy previously said that it had censured three other admirals for their roles in the widening scandal linked to Leonard Francis, a Singapore-based defense contractor who pleaded guilty in January to bribing a number of Navy officials.

Francis admitted that his company -- Glenn Defense Marine Asia (GDMA), which provided port services -- plied naval officers with cash, prostitutes, Cuban cigars and Kobe beef to ensure US Navy ships stopped at ports where GDMA operated.

Francis earned the nickname "Fat Leonard" in maritime circles because of his girth.

Benowitz underlined that Gilbeau was admitting to making a false statement to investigators and was not confessing to taking bribes.

"Rear Admiral Gilbeau did in fact make a false statement during the course of an important investigation," Benowitz said.

"In this unfortunate situation, he accepts responsibility for the decisions he made and for his conduct."

He added that Gilbeau potentially could be sent to prison for the charge.

"We are fighting extremely hard to ensure that he does not receive any incarceration," Benowitz said, noting Gilbeau's distinguished 37-year career during which he was awarded the Bronze Star and Purple Heart.

He did not provide details on the false statement.

The corruption scandal has shaken the American navy, with several officers pleading guilty and another arrested in the case.

In March, Captain Daniel Dusek was sentenced to 46 months in prison for giving classified information to GDMA in exchange for prostitutes and lavish gifts.

He was also ordered to pay a $70,000 fine and $30,000 in restitution to the navy.

In one instance, according to court records, Dusek arranged for the aircraft carrier USS Abraham Lincoln to stop at a port terminal in Malaysia owned by Francis.

The 2010 port visit cost the United States about $1.6 million, officials said.

As part of his guilty plea, Francis admitted he bilked the US military out of tens of millions of dollars by routinely overbilling for fuel, tugboat services and sewage disposal.

He agreed to forfeit $35 million that he made in the scheme and to repay the navy whatever amount the court decides.