Pizzas galore!

Christina Ramires, a Brazilian journalist who lives in the flat opposite Mr Bonomo's, said that a Spanish neighbour had seen two men banging on the window of the flat from the outside. "The Spanish woman said they were wearing hats ... then she heard a very strong sound, a bomb," she said.

A man who lives upstairs in the same block, who would only give his initials as HC, said: "I heard one loud clear bang, then two quieter bangs which shook the whole building. It was like someone dropping a fridge. I didn't hear anything before that."

Mr Duthie admitted that police did not yet know why the two young men were killed, nor by whom, but said that Scotland Yard was devoting its full resources to the inquiry.

He said forensic examinations were at an early stage at the "extremely complex scene", which had been left in disarray.

The detective said that Mr Ferez, who lived at another south London address, was visiting his friend when the attack took place.

Asked to describe the attack, he said: "I would not say this was a professional attack. I would say it was a frenzied, horrible, horrific attack. I imagine it would take some considerable amount of time to inflict the nature of the injuries."

One lead being followed by police is that the flat in New Cross, which was being rented by Mr Bonomo, was burgled only six days earlier, although Mr Duthie expressed doubt - given the level of violence - that the two men were killed during a follow-up visit. The keys to the flat may have been stolen, however, during last week's burglary.

The detective appealed to residents of New Cross to contact police or Crimestoppers on 0800 555 111 if they saw anything suspicious at around 9.30pm on Sunday.

"I also appeal to those people who work with Laurent and Gabriel at Imperial College. What were they like? Where did they go? Who did they meet? Where did they socialise?" he asked.

Imperial Rector Sir Roy Anderson expressed his shock and sadness at the news. He said:

"Our immediate thoughts are with their families. Laurent and Gabriel had bright futures ahead of them and it is dreadful that their lives should end so soon.

"I would also like to offer my support to the Imperial community as we mourn the loss of two young members. We offer our sympathies to those who knew and worked with Laurent and Gabriel. We are thinking of you during this very difficult time."

Times Recommends

• Oh no, Mr Darling: you have failed
• BBC survives dogfight over Kennel Club expose
• Where the Rosetta belongs can’t be set in stone