Robbery may have been motive for murder of French students

Detectives investigating the murders of two French students in London fear they were tied up and tortured for computer games and the codes to their bankcards.

The cards and two Sony PSP consoles – retail value £100 each – are thought to have been stolen from the flat in which Laurent Bonomo and Gabriel Ferez, both 23, were gagged, tied to chairs, stabbed 243 times and set on fire. A laptop computer was stolen from the property six days before the murders.

The bioengineering researchers, who were on a three-month placement at Imperial College London from the Ecole Polytechnique Clermont-Ferrand, were murdered in M. Bonomo's ground-floor bedsit in New Cross, south London, on Sunday night. The killings have baffled police officers, many of whom say they have never seen such violence. The strongest line of inquiry is that the men were targeted by a burglar who raided the flat earlier in the week. During that break-in the burglar was disturbed by M. Bonomo who was emerging from the shower. They are investigating whether a set of keys was taken, which would explain the absence of forced entry on Sunday.

Scotland Yard issued an appeal to anybody who may have been offered either the cards or the consoles. The force has received 25 calls after yesterday's appeal to the public over the deaths, several of which focus on the sighting of a white male seen running away from the flat after an explosion. Police have not ruled out the possible involvement of at least one other killer.

"We are keen to hear from anyone who has recently been offered a laptop and two personal game consoles, or knows someone who has unexpectedly come to have them," said Detective Chief Inspector Mick Duthie.

"A black Packard Bell laptop was taken during a burglary that took place between 5am and 6am on the morning of 23 June.

"The search of the address is not yet completed, but we have established that two Sony PSPs are missing and believe they were taken during the incident on Sunday when the two men were killed."

The bodies of M. Bonomo and M. Ferez were discovered late on Sunday evening after reports of a fire at the property. It was thought at first that they died in the fire but a pathologist later discovered that M. Bonomo had been stabbed 196 times, while M. Ferez was stabbed 47 times. Det Ch Insp Duthie said they were the worst injuries he had seen.

M. Bonomo's cousin Leo Bonomo, 51, visited the crime scene yesterday. "Our family in Europe are very shocked," he said. "There are slightly different cultures between here and mainland Europe. I think it's getting terrible over here. Knife crime is getting ridiculous and I know the Government are trying their best but a deterrent punishment is really the way to go."