Pakistan cricket coach Bob Woolmer's death at the World Cup on Sunday is now being treated as "suspicious" by Jamaican police, the deputy commissioner Mark Shields told a news conference on Tuesday.

"Having met the pathologist, medical personnel and other investigators, there is now sufficient information to continue a full investigation into the circumstances surrounding the death of Mr Woolmer which we are now treating as suspicious," Shields said, reading a short statement.

"We have already informed the Woolmer family of this development and we are also in close contact with the Pakistan team management, Cricket World Cup and the ICC (International Cricket Council) to ensure that all the parties are kept informed of the ongoing investigation."

One of the top coaches in the world, Woolmer, 58, was found unconscious in his Kingston hotel room on Sunday less than 24 hours after their World Cup defeat by Ireland and pronounced dead in hospital later that day.

Reports from the Pakistan camp at the time said that Woolmer was discovered by hotel staff lying on the floor in his room at the Jamaica Pegasus Hotel with his mouth wide open.

Blood was discovered on the bathroom floor, there was vomit on the walls and signs of diarrhoea.

Woolmer might have been murdered because marks were found around his neck, the popular cricket website cricinfo.com said, citing unconfirmed reports.

Shields would not speculate on the cause of Woolmer's death. "It would be inappropriate for me to make any comment at this stage as we have still not got the final official report from the pathologists," he said.

Pakistan were considered one of the leading contenders to win a title they claimed in 1992 but the shock defeat to debutants Ireland is one of the biggest upsets in the history of the 32-year tournament.

Coupled with an opening-day defeat by hosts West Indies, it led to their exit with one group game still to play.

The elimination was greeted with fury by fans back home in the cricket-crazy nation who burned effigies of the players.

"Obviously 'suspicious' could be anything at this moment," Pakistan team spokesman Pervez Mir said.

"It could be something serious, it could be something not serious. We have a man who is down and we don't know the reason why."

Talat Ali, the Pakistan team manager, told Geo TV they had not been given full details by the police. "They have not made any reference to poisoning or anything yet, as some reports are suggesting," Ali said. "There is no information at all that poison could be involved. Investigations will carry on so we cannot come to any conclusions right now."

Ali denied Pakistan were not allowed to travel. "There are no police restrictions on the team," he said. "As planned for now, we are flying back on Saturday."

Shields told reporters that "we have no suspects".

The governing body, the ICC, refused to comment when contacted by Reuters on the police statement.