Police Commissioner Lucius Thomas said in a statement that the pathologist report found Bob Woolmer's death was due to "asphyxia as a result of manual strangulation."
The statement, which was read by a police spokesman at the Jamaica Pegasus Hotel where Woolmer died on Sunday, said police were now treating the case as a murder investigation. Police said they were seeking witnesses to the crime.
"It is our belief that those associated with or having access with Mr. Woolmer may have vital information to assist this inquiry," Thomas said in the statement.
Woolmer, 58, was found unconscious in his blood- and vomit-splattered hotel room in Jamaica on Sunday, a day after his team's upset loss to Ireland on St. Patrick's Day sealed Pakistan's ouster from the tournament. He was later declared dead at a hospital.
Pakistan cricketers were fingerprinted and interviewed on Thursday by police investigating his death. They were allowed to leave the hotel in the afternoon and travel to Montego Bay.
No arrests have been made and there are no suspects in the case, police said.
It was not clear if the team would be asked to remain in Jamaica pending the investigation, but Mark Shields, a deputy police commissioner at the press conference, said the players have pledged full cooperation whether they are on the Caribbean island or back home in Pakistan.
Earlier Thursday, Assistant Police Commissioner Les Green, formerly of Scotland Yard, said the team was fingerprinted as part of standard procedure "to eliminate persons from fingerprints which would be found in the room."
"After a thorough investigation, fingerprints not belonging to Mr. Woolmer were found in the room," he told The Associated Press.
On Wednesday, a forensics team spent hours combing Woolmer's room on the 12th floor and reviewing security cameras from the hotel in Kingston.
Investigators had called in an American pathologist to help determine the cause of death amid local media reports that Woolmer had been strangled. An initial autopsy was inconclusive.
Shields declined to comment when asked about media reports describing the condition of Woolmer's body.
"There are some issues surrounding marks on his body, but for the moment I would rather we stick to the cause of death, which is asphyxia," he said.
Woolmer's wife, Gill, said Thursday in an interview from South Africa with Britain's Sky TV that she had not ruled out that her husband was murdered.
"I mean some of the cricketing fraternity, fans are extremely volatile and passionate about the game and what happens in the game, and also a lot of it in Asia, so I suppose there is always the possibility that it could be that (murder)," she said.
Woolmer's death has caused a sensation in the proper world of cricket and left the Pakistan national team in tatters and tears. Team captain Inzamam-ul-Haq announced his resignation and retirement from one-day cricket after Woolmer's death, then led Pakistan to an emotional victory Wednesday against Zimbabwe.
The burly, bearded team captain left the field weeping after the victory he dedicated to Woolmer. "He's not in this world now and every Pakistani and every cricket lover is sad," he said.
Woolmer, who is British, was born in India, played for England and recently split his time between Pakistan and South Africa. He is being accorded hero status in Pakistan after his death. Pakistani President Gen. Pervez Musharraf said he would be awarded the Sitara-e-Imtiaz, or Star of Excellence, for his contribution to sport.