Philippine police killed a town mayor linked to illegal drugs while he was helpless in a prison cell, justice department investigators alleged.

The National Bureau of Investigation said on Tuesday that it filed murder complaints against two dozen police officers and personnel last week after a probe showed they shot dead Mayor Rolando Espinosa and his cellmate Raul Yap in the central province of Leyte in November.

“The pieces of evidence, both testimonial and the forensic evidence, all agree. We believe we have a very strong case,” said Ferdinand Lavin, the NBI’s deputy director.

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Prosecutors will rule whether there is enough evidence to indict the policemen.

The finding contradicted claims by the accused and President Rodrigo Duterte that the victims were killed in a gun battle.

Duterte had accused Espinosa, mayor of the town of Albuera in the eastern province of Leyte, of being a drug lord. He had initially given police “shoot-to-kill” orders if Espinosa did not surrender, prompting the mayor to turn himself in.

NBI said the policemen most likely planted pistols and illegal drugs in their jail cells to justify a police raid.

‘Shoot-to-kill’

A few days before police raided the Leyte jail, authorities made a thorough search of the detention centre but found no guns or illegal drugs, so it was impossible for Espinosa and Yap to have weapons and narcotics in their cells, the NBI said.

Duterte, 71, won May elections in a landslide on a promise to kill thousands of criminals to prevent the Philippines from becoming a narco-state.

Monday’s accusations deepened concerns that police were carrying out summary executions as part of Duterte’s controversial “war on drugs”, which has claimed more than 5,100 lives in about five months.

In a speech late on Monday, Duterte defended the police who killed Espinosa and said he believed their version of events.

“Do not force me to believe the theories and assumptions, even with the witnesses, that the mayor was killed [illegally] in the prison,” he said.

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Duterte had previously signalled that he was happy Espinosa had been shot dead.

“You have here a guy, a government employee, using his office and money of government, cooking [illegal drugs] and destroying the lives of so many millions of Filipinos. So what is there for me to say about it?” he said last month.

Duterte’s police chief initially stood down the police officer in charge of the raid pending an investigation, but the president immediately reinstated him.