SAN DIEGO (Reuters) - A U.S. Navy rear admiral pleaded guilty on Thursday to a charge of lying to federal investigators, making him the highest-ranking officer to be convicted in the expanding “Fat Leonard” bribery case.

U.S. Navy Rear Admiral Robert Gilbeau is seen in an undated official picture from the U.S. Navy. Gilbeau will plead guilty June 9, 2016 to lying to federal investigators, the Washington Post reported. US Navy/Handout via Reuters

Robert Gilbeau, 55, a special assistant to the chief of the Navy Supply Corps, appeared in U.S. District Court in San Diego late Thursday afternoon, accompanied by his lawyer and a fluffy white dog he said helped him monitor his health.

Prosecutors said Gilbeau lied when he told investigators that he had not accepted gifts from Leonard Glenn Francis, whose contracts to clean, stock and maintain U.S. Pacific Fleet ships are at the center of the $30 million bribery case.

“He lied to federal investigators to conceal his illicit years-long relationship with Leonard Glenn Francis,” Assistant U.S. Attorney Mark Pletcher told reporters after the hearing.

Neither Gilbeau nor his attorney agreed to comment on the case.

Guilbeau’s guilty plea brings to 14 the number of people charged in the Singapore-based case, including Francis, the former chief executive of Glenn Defense Marine Asia. The Malaysian businessman also known as “Fat Leonard” pleaded guilty last year to bribery charges. Nine of the 13 previously charged have pleaded guilty.

Last month, a federal judge in San Diego sentenced U.S. Navy Captain Daniel Dusek, 49, to 46 months in prison in the case.

Dusek pleaded guilty last year to a charge of conspiracy to commit bribery after admitting he accepted services from prostitutes, luxury hotel stays, alcohol and other gifts in exchange for giving classified information to the company.

Three current and former U.S. Navy officers were charged with participating in the scheme on May 27, the U.S. Justice Department said.

In a plea agreement with prosecutors, Gilbeau agreed to pay $50,000 in restitution to the Navy as well as a $100,000 fine, said Kelly Thornton, spokeswoman for the U.S. Attorney’s office in San Diego.

He also faces up to five years in prison, although prosecutors have agreed to seek a sentence of 12 to 18 months, she said.

He was released Thursday on $75,000 bail and his sentencing date was set for Aug. 26.