MANILA - Two Philippine policemen have been charged with murder over the shooting death of two gangsters in their custody, Interior Secretary Manuel Roxas said Thursday.
Fourteen other officers were charged with perjury for trying to cover up the crime, Roxas told a news conference.
The July 15 killings highlighted the huge problems of the 150,000-member force, widely considered one of the most corrupt government agencies in the Philippines.
"We don't know whether they were killed to silence them. The point is they were shot dead while in the custody of the police, and the first story (the policemen) gave turned out to be false," Roxas told reporters.
Investigators are also looking into the possibility that the two gangsters were killed to stop them revealing their rumoured government connections, he added.
One of the slain men, Ricky Cadavero, had escaped last year from a Manila prison where he was serving terms for armed robbery.
Police initially said the pair were captured earlier this month, but were later shot dead by their police guards inside a van that was taking them to jail.
According to the police account the two convicts, both handcuffed, attempted to grab the policemen's guns during a rescue attempt by fellow gang members riding motorcyles.
However Roxas said one of the officers involved in the cover-up later confessed that the purported ambush did not happen.
The officer said he was ordered by a superior to shoot at the police van to make it look like it had been hit in an ambush, Roxas added.
He named those charged with murder as Senior Inspector Manuel Magat and Inspector Efren Oco.
President Benigno Aquino in his annual speech to parliament on Monday singled the case out as an example of potential police links to criminal gangs.
Aquino is closely watching the case as well as other other efforts to root out corruption in the force, his spokesman Edwin Lacierda said Thursday.
"The president always says that where the evidence leads, we will follow... no one is to be protected," Lacierda told reporters.
The shooting happened shortly after a police unit in the southern city of Davao was put under investigation for the alleged murder of at least one member of a kidnap gang during an operation that rescued a woman hostage.