Most believe male rape - which does not exist in law - goes largely unreported, as did child sex abuse 20 years ago. Official statistics do not record it, including attacks listed under figures for buggery.
Ernest Woollett, co-ordinator of the male rape helpline, Survivors, said: 'I personally dealt with 70 victims last year of whom only three reported their attacks to the police.' Superintendent Maria Wallace, of the Association of Chief Police Officers' crime committee, said the ACPO was entirely dependent on Home Office figures: 'We don't have any national statistics but I would suggest any we do have are the tip of the iceberg.'
The increase in the number of men who did come forward in London could be a result, Ms Wallace said, of improved public confidence in the way police treat victims of sex crime: 'From a personal point of view there are still grave questions about the way the victims may be treated throughout the prosecution service. Where I think there is sympathy for a woman rape victim, there is a lack of understanding for male victims. The question behind closed doors will not be 'is he all right?' but 'is he gay?'.'
The misconception that male rape is a homosexual crime is common. Studies of the few victims who have identified themselves revealed that often both the attacker and the victim were heterosexual. Conquering armies in Roman times did it to their vanquished enemies and there are reports of similar abuses going on in the former Yugoslavia.
'This is a crime of power,' one police officer said last week. 'If you derive power from dominating and defiling a woman, how much more do you get from doing it to a man?'
A pilot scheme was launched two years ago by Scotland Yard to train male police 'chaperones' to take statements from victims of serious sex assault. One chaperone said last week that it was vital that men disclosed the attack to a police officer first: 'Even though it is hard for them, they must report the attack immediately and give us a chance to collect the forensic material. This could happen to anyone. Heterosexual men who regard themselves as straight, completely normal in their view, have been attacked. Our problem is that we don't have any idea who the average victim is or how many there are because they don't come forward.'
One such victim, Jeremy Williams, 21, was raped last February in a car park in central London. Fitzroy Hemans, 45, from Islington, north London, offered him some drugs and then produced a knife before attacking him. Hemans was sentenced to 10 years in the Old Bailey last December for attacks on Mr Williams and another young man.
Yesterday Mr Williams, now married with a baby son, said anyone who is attacked should call the police: 'Maybe you can stop somebody else being attacked. As long as people like this are free they will keep attacking people.'
He said he still feels sick about being raped: 'I get down sometimes. I can drink and get depressed. I get angry. If I had him in front of me and I had a baseball bat I could still club him. I think I could still kill him. But if I let him get to me then it would be like he's still got some power over me and he hasn't because he's in prison.'
The maximum sentence for forced buggery is 10 years. The Labour MP Harry Cohen is trying to get it increased to life.