Investigators in Jamaica say they have recovered CCTV footage from the hotel corridor where murdered cricket coach Bob Woolmer's room was located.
Woolmer's body will remain on the island till after an inquest
Deputy police commissioner Mark Shields said they were hopeful that the footage from the 12th floor could yield images of whoever strangled Woolmer last week.
He said the tapes are now in a secure location and being converted digitally.
The news came as it was confirmed Woolmer had announced just prior to his death that he planned to retire.
Dr Nasim Ashraf, chairman of the Pakistan Cricket Board, said Woolmer sent him an e-mail announcing his retirement after the team surprisingly lost their World Cup match to Ireland on 17 March.
Ashraf said: "It was the email of a man who had been deeply hurt. He said that the boys gave it their best to the last minute.
"In that email he had shared some of his thoughts, he told me that he was hanging up his boots and retiring from international coaching.
"However he told me that he would continue to be involved in cricket at the grassroots level."
Pakistan's players arrived in London from Jamaica on Monday, after police investigating the murder questioned them.
Suggestions of a heated row between Pakistan cricketers and Woolmer hours before his murder have been denied by a team official.
Spokesman Pervez Mir said there was silence, not confrontation, in the wake of the defeat by Ireland.
Woolmer was found strangled in his hotel room early the next day.
Mr Shields said that the CCTV cameras were installed at either end of the corridor and that, while they did not show Woolmer's actual room, they should tell police who came in and out of the passageway.
"They are crucial as they may give us an image of the murderer or murderers of Bob Woolmer," he said.
Mr Shields said that the footage would now be converted onto a digital format so that it could be properly examined and to ensure that the original film did not get damaged in any way.
Inzamam was one of three squad members questioned
Pakistan captain Inzamam-ul-Haq, team manager Talat Ali and assistant coach Mushtaq Ahmed spoke to police on Saturday.
Mr Shields said the extra questioning had been only a formality.
The squad has now landed in Britain and hopes to leave for Pakistan on Sunday night, Mr Mir told the BBC.
Speaking after the squad arrived at London's Heathrow airport, Mr Mir said the players were shell-shocked by the loss to Ireland, which saw Pakistan eliminated from the World Cup.
The team has been dogged for years by damaging internal rifts and suggestions of power struggles between Inzamam and Woolmer.
However, Mr Mir denied widespread reports of any clash with the coach.
"There was no confrontation in the dressing room. There was no confrontation in the bus. In fact it was a stunned silence."
Woolmer then went to his room with a final word for his captain, telling Inzamam-ul-Haq "it is a sad thing we are parting this way".
The circumstances surrounding the defeat by Ireland have become a key part of the police investigation into Woolmer's murder.
Pakistan's players and management touched down in London shortly before midday on Sunday and were ushered away from the waiting media.
Woolmer's body is being kept in Kingston until an inquest is held.
Detectives in Jamaica believe Woolmer probably knew his killer - or killers - as there were no signs of forced entry into his room and none of his belongings had been stolen.
Pakistan's players had already given police DNA samples and fingerprints as part of the probe into Mr Woolmer's murder.
However, Mushtaq was confident that none of the Pakistan team could be implicated in Woolmer's murder.
"God willing, I am 110% sure [that none of the Pakistan team were involved]," he said.
Two Pakistan government officials have travelled to the island to liaise with the Jamaican authorities over the investigation.