Jamaican police probing the murder of Pakistan's cricket coach Bob Woolmer say they could be searching for more than one attacker.
Bob Woolmer had coached Pakistan since 2004
Police say Woolmer may have known his killer or killers, and are studying video footage from the Pegasus Hotel.
Members of the Pakistan team and staff have already been interviewed, and now plan to return home at the weekend.
Woolmer, who was 58, was strangled in his room hours after Pakistan lost to Ireland in the cricket World Cup.
The defeat dumped Pakistan - a talented but erratic team ranked fourth in the world - out of the competition.
A post-mortem examination established that the former England player had died as a result of "manual strangulation", police commissioner Lucius Thomas said.
"In these circumstances, the matter of Woolmer's death is now being treated as murder," he told a news conference.
Lines of inquiry
Suspicions that the coach may have known anyone who attacked him have been raised after it emerged there were no signs of forced entry at his hotel room in Kingston and none of his possessions were taken.
BOB WOOLMER TIMELINE
1. 17 Mar: Ireland beat Pakistan
2. 18 Mar, 10.45am: Woolmer found unconscious in hotel room
3. 18 Mar, 12.14pm: Pronounced dead at hospital
Photo: Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center.
Woolmer was found unconscious by staff at the Pegasus Hotel on Sunday morning.
The deputy commissioner of the Jamaican police, Mark Shields, said this might now be a hunt for more than one killer, and urged the perpetrators to hand themselves in.
"Bob was a large man. It would have taken some significant force to subdue him," he said, adding that police were ruling nothing out and had "lots of lines of inquiry".
"I have to say at this stage that it looks as if it may be somebody who's somehow linked to him, because clearly he let somebody into his hotel room and it may be that he knew who that person was," Mr Shields told the BBC.
Mr Shields also "unequivocally dismissed" Indian television reports that arrests had been made.
"That's nonsense, as far as I'm concerned. There's actually no truth in that," he said.
The BBC's Andy Gallacher in Kingston says that Bob Woolmer's murder has stunned the cricketing world and left the World Cup in disarray.
Speculation that this may be connected to gambling cartels is only adding to the confusion surrounding his tragic death, our correspondent says.
On Thursday, Jamaican police questioned members of Pakistan's cricket squad over the death.
After being interviewed for about an hour and fingerprinted, the team left for the resort of Montego Bay.
They are planning to return to Pakistan on Saturday.
Pakistan team spokesman Pervez Jamil Mir said the players were "in a state of shock" over the news that Mr Woolmer had been killed.
However, the sport's governing body, the International Cricket Council (ICC), said the competition would continue as planned to "demonstrate that cricket cannot be put off by a cowardly criminal act".
ICC chief executive Malcolm Speed said the entire cricket community was shocked by the death of the former England Test batsman.
He said: "Everyone connected with this event will assist the police in any way possible to ensure the truth emerges."
Speed confirmed the ICC's Anti-Corruption Unit would be liaising with police in case there was any link to illegal betting within the game.
"We have people at every cricket match, they're observing what goes on. We have a very extensive database of connections to bookmakers and betters.
"If there is a link there we want to know about it and we will deal with it," he added.
During his career, Woolmer also coached South Africa and enjoyed great success coaching in English county cricket, winning four trophies in two seasons with Warwickshire.