Facebook has not passed a single complaint about suspected paedophiles grooming vulnerable child users to police in Britain, it was claimed today.

Jim Gamble, who heads Britain's response to safeguarding youngsters online, said he has "real concerns" about the internet giant's work to protect children.

He challenged the company to reveal the evidence that its staff are working to disrupt devious criminals and bullies who lurk online.

Mr Gamble said investigators received 252 complaints about sexual grooming, bullying and hacking from Facebook users in the first three months of this year.

But the former National Crime Squad deputy director said none of these were provided by the company itself and some were passed through rival services.

His comments were the latest salvo in an increasingly bitter feud over Facebook's refusal to add a "panic" button to its site's most popular pages.

The Child Exploitation and Online Protection Centre (Ceop), wants the button, which enables users to report abuse, to be given prominent use.

Mr Gamble, who leads Ceop, is heading to a crunch meeting with Facebook bosses in Washington DC on Monday where he will call for them to break the deadlock.

Speaking in central London today, Mr Gamble said it is a "real concern" that Facebook is not passing information to police.

He said: "Facebook say their system is robust and we have no reason not to believe them. Our reports are increasing month on month.

"In the first quarter of this year we have had 252 complaints about Facebook. None of these complaints came direct from Facebook.

"If their system is so robust and they are receiving so many reports and concerns from young people, then where are they?"

Mr Gamble said the number of reports linked to Facebook is soaring, with the latest number of complaints almost equalling the 297 received in 2009.

He said the internet company is good at removing pornography and other obscene content, as it is required to do so by law in the United States.

He added: "I believe Facebook are confusing their approach to content with their approach to behaviour and that is the root of the problem.

"That is where predators will go online, engage the young and vulnerable, and lure them offline where they can abuse them.

"In many cases we are also seeing young people in the online environment being bullied to the point of suicide.

"I am meeting with Facebook in Washington DC and I will be presenting them with the facts as we see them.

"I will be asking for the evidence to show what they are doing to protect children in the UK. I have yet to see any evidence that they have passed any information to us."

Officials at Ceop receive up to 800 reports every month from internet users who suspect others of grooming, bullying, fraud and other crimes.

Of the 252 complaints about Facebook received between January and March, two out of five were linked to sexual grooming.

Senior staff at the crime-fighting organisation said they are "baffled" and "confused" at Facebook's continued reluctance to adopt the free service.

The issue was thrust into the headlines last month following the conviction of a serial rapist for the murder of schoolgirl Ashleigh Hall.

Peter Chapman posed as a young boy on the site to lure the 17-year-old to her death in Sedgefield, County Durham.

Mr Gamble said proposals to put the button on a special separate safety page were not acceptable as few would read them.

He said its prominent use would act like a burglar alarm on a house, deterring intruders from even attempting to commit a crime.

Mr Gamble said the actions of young people reporting suspicions through the button have led to paedophiles being jailed indefinitely and saved others from abduction.

In one case a paedophile pretended to be a young girl to persuade another to pose for photographs in her underwear.

Once the images were posted online the attacker used the images to blackmail his victim into more extreme acts.

Mr Gamble said the button has cross-party political support in Britain, and is backed by police chiefs and leading child and anti-bullying charities.

Speaking last month, Prime Minister Gordon Brown said he was expecting progress from Facebook on the panic button within days.

Mr Gamble added: "Is Facebook so arrogant that it does not matter what the collective child protection community think?"

A spokesman for Facebook said: "We take the issue of safety very seriously, and recently met the Home Secretary to discuss online safety.

"We are due to meet with Ceop next week to talk them through our safety strategy. We will wait to have this meeting prior to sharing our plans more widely with the public soon afterwards."