A fourth US Navy officer has been charged with leaking information to a foreign defense contractor in exchange for cash and other gifts in a widening bribery scandal, officials said Thursday.

Petty Officer First Class Dan Layug, 27, was arrested Wednesday in San Diego and appeared in court Thursday, when a judge released him with GPS monitoring in lieu of a $100,000 bond.

He is accused of accepting bribes in return for giving classified and sensitive US Navy information to employees of Glenn Defense Marine Asia, a defense contractor at the center of the scandal.

Layug allegedly used his position at a US Navy facility in Yokosuka, Japan, to gain access to US Navy ship schedules and other information, which he provided to GDMA's vice president of global operations.

In exchange, GDMA gave Layug monthly cash payments of $1,000 as well as electronic gadgets from a list the officer requested, including an iPad, a high-end camera, an iPhone 5, a Samsung S4 cell phone and an iPad mini.

"The camera is awesome bro! Thanks a lot! Been a while since I had a new gadget!" he allegedly wrote in an email to his GDMA contact after sending his "bucket list" of desired gadgets.

The new charges were revealed in a criminal complaint unsealed by prosecutors in San Diego on Thursday.

Last month, Singapore businessman Alex Wisidagama pleaded guilty to defrauding the United States as part of the bribery scandal involving contracting services for US Navy ships.

The 38-year-old admitted to submitting fake invoices to overcharge the US Navy for fuel, port tariffs and other services.

He was the second person to plead guilty in the case that has rocked the US Navy and ensnared several officers, fueling concerns about a possible ethics crisis in the military's senior ranks.

In December, former Naval Criminal Investigative Service special agent John Beliveau admitted providing the ship supply company with sensitive information in return for cash, hotel rooms and prostitutes.

Wisidagama is due to be sentenced on June 13. His cousin Leonard Francis, who owns the ship supply firm GDMA, is a key player in the case.

According to prosecutors, officers dubbed Francis "Fat Leonard" for his girth and his penchant for allegedly showering favors on sailors in return for preferential treatment for his firm.