A US naval commander has been sacked over his alleged links to an elaborate bribery scandal that involved prostitutes, luxury travel and multimillion-dollar government contracts, officials said Friday.

Captain Daniel Dusek, commanding officer of the USS Bonhomme Richard based at the port of Sasebo, Japan, was relieved of his duties "due to a loss of confidence in his ability to command," the Navy said in a statement.

Dusek is under investigation by the Justice Department in a widening scandal that allegedly had a Singapore-based company offering cash, prostitutes and luxury travel in return for contracts to provide support services to naval ships, a military official said on condition of anonymity.

Although Dusek has not been charged with a crime, his superiors "determined the investigation negatively affected Dusek's leadership ability and was a distraction to the command mission," according to the Navy statement.

The Bonhomme Richard, an amphibious assault ship that sailors call the "Bonny Dick," is the flagship of an amphibious ready group for the Seventh Fleet.

Dusek, who had taken command of the warship in June 2012 and had been decorated for his previous missions, has been temporarily assigned to Expeditionary Strike Group Seven, officials said.

Another naval officer, Commander Michael Misiewicz, who commanded a destroyer and served as deputy operations officer for the head of the Seventh Fleet in the Pacific, has been charged in the case, as well as a supervisory special agent for the Naval Criminal Investigative Service (NCIS).

Federal authorities allege that Misiewicz, who fled the Khmer Rouge regime in Cambodia as a child and was adopted by an American woman, directed ships to certain ports where the Singapore-based firm overcharged for fuel, food, water and other services.

Misiewicz in return was allegedly given access to prostitutes, free travel and even tickets to a Lady Gaga concert.

The firm cited by federal prosecutors is Glenn Defense Marine Asia, and the CEO, Leonard Francis, has been charged, along with Misiewicz and the NCIS agent, with conspiracy to commit bribery.

In one email, GDMA's chief refers to certain prostitutes in Thailand as his "Elite Thai Seal Team."

After naval authorities began investigating the firm for possible overcharging for services, the accused NCIS agent, John Beliveau, allegedly supplied the head of GDMA with sensitive information about the probe, according to federal prosecutors.

The US Attorney's Office in San Diego first announced the case last month.