SAN DIEGO (REUTERS) - A Singapore-based defence contractor accused of plying US Navy officials with cash, travel, concerts and prostitutes in a bid to win business for his firm was ordered held without bail on Monday pending trial.

A federal judge, in reversing a tentative decision last week to grant bail to Malaysian citizen Leonard Glenn Francis, said Francis represented a potential flight risk and cited the seriousness of the crimes he is accused of committing.

Francis, a 49-year-old businessman, was arrested in San Diego on Sept 16.

A federal magistrate granted him US$1.1 million (S$1.4 million) bail on Thursday but stayed her ruling pending a review by another judge.

Six Navy officers and a Navy criminal investigator have also been touched by allegations in the probe.

US Navy Commander Michael Misiewicz and Navy criminal investigations special agent John Beliveau were arrested on Sept 16, the same time as Francis, and charged with conspiracy to commit bribery.

Commander Jose Luis Sanchez was arrested and charged earlier this month with accepting prostitutes, luxury travel and $100,000 in cash from Francis. Three other Navy officers have been suspended or placed on leave but not charged in the case.