How a 'terrorist' in a frock made fools of the prince's guards

Amid hundreds of people kitted out as lions, tigers, witch doctors and Robert Redford outside Windsor Castle on Saturday evening, the one dressed as Osama bin Laden probably only seemed a little out of place.

Onlookers and guests attending Prince Williams's lavish Out of Africa-themed 21st Birthday bash almost certainly thought he was just another guest with perhaps a slightly misplaced sense of geography and a sick sense of humour - one of the Prince's mates from St Andrews University, perhaps. Or maybe it was their friend, society girl Tara Palmer-Tomkinson turning up in another misjudged party frock. It was a bright pink Osama bin Laden dress, after all. Complete with turban, beard and sunglasses.

Since some of them probably remembered seeing the fellow at Royal Ascot last week, they may have assumed that he was, well, simply one of us.

"Happy birthday. Out of Africa, I'm out of this world," he shouted, lifting up his skirt to reveal a bushy merkin, a wig around the pubic area. "The real hair to the throne," he quipped. In fact, he was Aaron Barschak, aka The Comedy Terrorist, son of a north London property developer and a relatively recent arrival on the comedy club circuit, who really does dress up as an Osama look-alike and who has a sideline in gatecrashing other people's shows.

Saturday night, when he briefly joined Prince William on stage in the Great Hall inside Windsor to address the 300 party guests, including almost the entire Royal family and a fair selection of the nations glitterati was clearly his best gig yet. Mr Barschak's future dates at the Edinburgh Festival Fringe are likely to be a letdown in comparison, although, should the forces of law and order, currently in control of his destiny, allow him to attend, they will be probably be a sell-out.

How Mr Barschak gained access to the Castle was last night the subject of an investigation by embarrassed Scotland Yard officers who will have to report on the security failures to the Home Secretary, David Blunkett. There were no clues as to whether he had somehow obtained a genuine ticket, forged one or simply slipped past the security guards.

According to reports that filtered out from the event, just after 11pm and several hours after he had been seen outside the Castle, Mr Barschak stumbled onto the stage in the Great Hall, interrupting the Prince's thank you speech to his father and the Queen for organising the party.

Such was the nature of the event - a Botswanan band, model elephants, live monkeys, animal skins strewn around - most of the audience believed Mr Barschak was part of the entertainment. He was said to have grabbed the microphone before security guards and police took him out of the Great Hall. As he was led away he shouted: "You can see me next Monday,'' presumably a reference to today's newspapers. "I didn't know my brother could do an accent like that," said Prince William jokingly afterwards.

Mr Barschak was unavailable for interview yesterday, but his 72-year-old father, Fred, filled in the gaps in his CV. His son had done his A-levels at the prestigious and fee-paying City of London school before travelling to Bolivia, where he imported Western pop music records. He had studied acting in New York and really wanted to be a serious actor.

Fred Barschak said: "He has played every comedy club in London and many across the country. He is a wonderful mimic. He does a great Ali G and Gregory Peck, which came in handy recently. He created the Comedy Terrorist character."

He added: "He is a zany character with a zany sense of humour. But he is not a nutter."

Fred Barschak said his son manages to slip into high-profile events dressed as the al-Qa'ida leader by tucking his tunic under his shirt and trousers to avoid suspicion.

Occasions gatecrashed by Barschak include a speech by Ken Livingstone, the Mayor of London, during an anti-war rally in Hyde Park and a tribute to Spike Milligan at London's Guildhall, when he interrupted a sketch by Terry Jones, the former Monty Python member. More recently he interrupted camp comic Graham Norton during a charity performance at the Great Ormond Street Hospital for Children, when he arrested him in the name of the "comedy police". Some said he had a point. Earlier this month he was said to have thrown a can of paint over artist Jake Chapman, as he gave a lecture in Oxford on spontaneity in art. And last week he was at Royal Ascot, where he remained relatively unnoticed.

He was due to play at the Canal Cafe Theatre at a pub in west London earlier this month but the show never went ahead. Venue organiser Emma Taylor said: "I rang him ... but he did not seem to even know the show was going ahead. He said his show would be like a workshop and he called himself the Comedy Terrorist. You get all sorts in comedy."

Probably, Mr Barschak will not need to play pubs in the future. The celebrity agent Max Clifford said last night: "Before he was an unknown, now he is front-page news. But he is obviously only going to appeal to a certain type of audience that appreciates that kind of outrageous humour.''

And, if he can fit it in, there is one audience where he might go down a storm. The Students' Union at St Andrews University might want to book him for its next graduation night ball.

The naked paraglider, the cufflink thief and the palace intruder's bedside chat

March 1982: In the most infamous breach of royal security, Michael Fagan broke into the Queen's bedroom at Buckingham Palace, woke up Her Majesty and sat on the bed talking for 30 minutes. He was later jailed.

1990: Stephen Goulding, one of a large number of disturbed people to break into the grounds of royal palaces, claimed he was Prince Andrew. Other similar intruders have claimed to have important information about national security or to be infatuated with various royals.

July 1991: Kevin McMahon was arrested after his second sortie into the grounds of Buckingham Palace in a week; during the first, a helicopter carrying the Queen and the Duke of Edinburgh was forced to divert as he roamed the grounds.

July 1993: A group of women anti-nuclear protesters used ladders to climb into Buckingham Palace, cut barbed wire and came within yards of royal apartments. They sat singing and chanting on the lawn for 15 minutes.

February 1994: A naked paraglider, James 'Fanman' Miller, was fined £200 and deported to the United States after landing on the roof of Buckingham Palace.

February 1994: An intruder broke into the Prince of Wales's apartment at St James's Palace and stole cufflinks given to the Prince by Camilla Parker Bowles.

January 1995: John Gillard, 21, a student, drove 200 miles from his home in Yorkshire to ram his car at high speed into the gates of Buckingham Palace. One of the gates, weighing more than two tons, was ripped off its hinges.

December 2002: Another, drunken, late-night intruder in St James's Palace was apprehended while knocking at the door of the Princess Royal's bedroom, apparently in the belief she would know the way to Victoria Station.