A man is being questioned by detectives in connection with the murder of two French students, who may have been tortured for their bank details, after being arrested earlier today. 

Detectives suspect Laurent Bonomo and Gabriel Ferez, both 23, were killed in a robbery that escalated into the horrific double murder.

The Metropolitan Police said the 21-year-old man was arrested at 3.40am this morning and is in custody at a police station in south-east London.

It is understood that credit and charge cards are missing from the rented flat in New Cross, South-East London, where Mr Bonomo and Mr Ferez were gagged, tied to chairs, stabbed 243 times in the head, chest and back and finally set on fire.

Brutally murdered: Laurent Bonomo (left) and Gabriel Ferez were stabbed almost 250 times before their bodies were covered in an accelerant and set alight

They may have been tortured for hours to make them give up their PIN numbers.

Two new Sony PSP games consoles - worth £160 each - are also missing from Mr Bonomo's flat, fuelling the theory that the men were murdered in a robbery at the hands of crazed drug addicts.

Six days before the murders, Mr Bonomo disturbed an intruder who stole a laptop as he took an early morning shower. That theft and the murders may be connected.

Tribute: Laurent Bonomo's cousin Leo visits the flats today with flowers

The level of violence has led to speculation that the killer or killers were on crack cocaine when the bio-chemistry students were slaughtered on Sunday.

Last night the father of Mr Ferez paid tribute to his 'incredibly gifted son' who was studying with Mr Bonomo at Imperial College, London.

Speaking for the first time about the killings, Olivier Ferez, a nurse, told the Daily Mail: 'We are just in shock and completely devastated.

'Gabriel is, was, the most intelligent, affectionate, wonderful son anyone could ever want. He studied at the best university in France and then the best in England. He had such a bright future and now that has gone.'

Divorced Mr Ferez, who yesterday comforted his daughter Helene, 20, and 12-year-old
younger son at the family home, added: 'It is the worst nightmare for any parent.'

Rejane Ferez, Mr Ferez's grandmother, said he had been 'finding life in London tough'. 

She added: 'Gabriel loved travelling and had recently spent time in Mexico, but nothing had prepared him for London.'

She added: 'As well as all the usual problems, life in London could also be very lonely. Both Gabriel and Laurent were greatly looking forward to getting back home.'

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Tragic: Mr Bonomo, 23, with his fiancee Mary Bertez. Ms Bertez, also a student, has said their time together was the happiest of her life

The students were in the second year of a three-year master's degree in France and had been selected to take part in a three month research project at Imperial College.

They were due to return home later this month.

Mr Bonomo, from Velaux, near Marseille, and Mr Ferez, from Prouzel, near Amiens, were popular characters at the Polytech Clermont-Ferrand in central France.

Yesterday parents of fellow students in London demanded that their children be brought home.

University director Claude-Gilles Dussap said: 'I have had a number of calls from families saying they are scared about their son or daughter and want them to come home. They think London is dangerous.'

He added: 'I told them the same thing could happen here in France, in Paris or Lyon, it is just a freak terrible thing but it could have happened anywhere.'

Bound: Mr Ferez, 23, had been visiting his friend's flat when he was killed

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Manhunt: Forensic teams comb the flat and surrounding area for any clues about the killer. A white man was seen running from the flat after the explosion

Disarray: Inside Mr Bonomo's flat is a scene of chaos

The bodies of the 23-year-olds were found at Mr Bonomo's flat in the cul-de-sac of Sterling Gardens, New Cross, on Sunday night.

A white man was seen running away moments after an explosion.

Detective Chief Inspector Mick Duthie, leading the investigation, said: '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.

'A black Packard Bell laptop was taken during a burglary between 5am and 6am on June 23.'

Detectives have said the burglary in which the laptop was stolen could be linked to the murders as forensic experts have found no evidence of forced entry, suggesting a stolen set of keys may have been used.

Speaking outside the flat, Mr Duthie said the fire was started to destroy forensic evidence.'

He added: 'We are still looking into how many weapons were used. We haven't recovered any from the scene.'

He said 40 detectives were on the case, codenamed Operation Dockery.

Boarded up: Officers block off the windows of the ground-floor flat after they were blown out

Anyone with information should call the incident room on 020 8721 4155 or Crimestoppers anonymously on 0800 555 111.

The possible motives                                                        

Theft:
A burglar broke in to the bedsit six days earlier and stole a laptop. Did he return and torture his pleading victims in a bid to obtain more valuable items? Sources described this as a key line of the inquiry.

Drugs:
The ferocity of the murders has prompted speculation that the killer or killers could have been on crack cocaine - which can cause paranoia and extreme violence. Or, for whatever reason, did the men fall out with a local drug dealer?

Mental illness:
The violence could be the work of a psychopath or person with an acute personality disorder. Police will check on seriously mentally ill individuals in the area.

Sex:
Although neither victim suffered sexual injuries, police cannot rule out completely the possibility of a sexual motive. Did the killer or killers get a sadistic pleasure from inflicting unimaginable pain? Was there a bizarre homosexual motive?

Revenge:
Strong feelings of revenge can sometimes prompt horrific acts of violence. But police see no obvious reason why the men would attract such hostile feelings.

Mistaken identity :
Were the men mistaken for other individuals who were the intended targets?