A pathology report indicated that Pakistani cricket coach Bob Woolmer died of "manual strangulation," according to a statement from Jamaican police commissioner Lucius Thomas.
"In these circumstances, the matter of Mr. Woolmer's death is now being treated by the Jamaican police as a case of murder," the statement said Thursday night.
Police announced Tuesday that Woolmer's death was suspicious, two days after he was found unconscious in his room at the Pegasus Hotel. Woolmer, 58, was declared dead at a hospital soon after he was found.
Initial media reports indicated he died of a heart attack.
Woolmer's death came less than 24 hours after former world champion Pakistan was beaten and eliminated by the relatively unknown Irish team on St. Patrick's Day, one of the biggest shocks in World Cup cricket history. The loss on Saturday prompted outrage among the team's hardcore fans, with protesters burning effigies of Woolmer and the team captain in Karachi.
Asked about suspects, Deputy Police Commissioner Mark Shields would only say, "We have a few definite lines of inquiry," acknowledging later that betting on cricket matches was among them.
Shields urged people with any information about the case to come forward.
"It's a very busy hotel," he said. "I'm absolutely certain that someone saw something that could help us in this investigation."
Blood, vomit and diarrhea were splattered over the walls and floor of Woolmer's hotel bathroom, said Pakistan's team spokesman Pervez Mir Wednesday afternoon.
Police refused to comment on that report.
Earlier on Thursday, police fingerprinted all members of the Pakistani cricket team at the hotel, and they were to submit statements to police as part of the ongoing investigation, Mir said.
"It is standard procedure," Mir added. "Each of them will come along and give a written statement."
The players' hotel rooms were on the same floor as Woolmer's.
The team has been cleared to leave Kingston, and there was no reason to detain anyone, a Jamaican official said Thursday.
The team left the hotel secretly and was believed to be flying to Montego Bay, Jamaica, for two days' rest before returning to Pakistan.
Woolmer, who was English, played Test cricket for England in the mid-1970s. He later turned to coaching and coached the South African national team before taking over as Pakistan's coach in 2004.