News: Detectives investigating the murder of Bob Woolmer yesterday said they were decoding crucial CCTV footage which could reveal the identity of the Pakistan coach's killer.

Mark Shields, the former Scotland Yard superintendent who is number two in the Jamaican police force, said the new material was "critically important, because it may give us an image of the killer or killers".

The development came as the police defended their decision to let the Pakistan team fly home, via London.

Officers have begun to examine the CCTV footage, which has been digitalised. Mr Shields said he was optimistic that the quality of the pictures would be good enough to help determine who was present on the 12th floor of the Pegasus hotel in Kingston between 8.30pm on Saturday, March 17th, when Woolmer was last seen, and 10.45am on the Sunday, when a chambermaid found him lying lifeless in the bathroom. The film could also help to determine a precise time of death.

The CCTV cameras would have filmed anyone leaving or entering the lifts on Woolmer's floor of the 17-storey hotel, as well as anyone using the back service entry. However, there are no cameras along the corridor, which means that movement between rooms on the floor would be undetected.

As the Pakistan team left, having been knocked out of the World Cup, Shields said he was powerless to keep the team in Jamaica. To do so "would have been to use a sledgehammer to crack a nut. It would probably have caused a significant diplomatic incident and had an extremely adverse effect on the World Cup". There was insufficient evidence to hold anyone as a suspect at this time.

With speculation continuing to swirl around the relationship between Woolmer and players in the team, the squad began a two-day stopover in London before their return to Islamabad. At the Holiday Inn near Heathrow airport, the team's media manager, Pervez Jamil Mir, complained that the team was being kept in the dark on the police inquiry. "We still haven't been told officially in writing by the police how Mr Woolmer was murdered. We want the police to tell us what is going on," said Mir who added he had not been asked by the police to make any arrangements should the players be recalled to Jamaica.

"If the police want players for any further questioning, they are here to answer them," said Mir.

The murder hunt will now spread its net to other squads whose members were at the Pegasus hotel on the Sunday morning that Woolmer was found strangled in room 374.

Brian Lara, the West Indies captain, has been questioned and all members of the West Indies and Ireland teams will be asked to volunteer a statement, fingerprints and a DNA swab.

Several top managers and players from the Pakistan, West Indies and Ireland teams were staying on the 12th floor, including Lara, the Ireland captain Trent Johnson, Murray Stevenson, the Pakistan fitness trainer, Darren Lifson, another team manager, and the Pakistan player Danish Kaneria.

Inzamam-ul-Haq, the Pakistan captain, was also on the 12th floor until shortly before Woolmer's murder, when he moved to the fifth floor. He was questioned by police on Saturday about why he had changed rooms and told them he had wanted to be closer to the other players.

Talat Ali, the team manager, and Mushtaq Ahmed, its bowling coach, were also questioned to fill in holes in their earlier statements, police said.

Pakistan has asked to send a detective to Jamaica to investigate what it claims were links between an Indian bookmaker and the murder. A senior government official said that two Pakistan players told Jamaican police that Woolmer had a blazing argument with a bookmaker based in Mumbai on Saturday night.

"Bob Woolmer said he had just thrown a bookie out of his room. He didn't give any reasons," the official said. Shields said he was unaware of any bookmakers having stayed at the Pegasus, or any suggestions of Indian involvement.

• Guardian Service