As the September 11 anniversary approaches UK airport security is under scrutiny.

Transport secretary Alistair Darling met with airport bosses on Thursday, after a television company exposed serious security breaches at three British airports.

Reporters for a documentary by Meridian television successfully smuggled an imitation handgun onto a flight from Heathrow to Edinburgh, and a pair of scissors on flights from Gatwick and Southampton airports.

One, Mike Pearse, said he was "amazed" at how easy it was to do.

"I was amazed how easy it was to walk through Heathrow security with a gun undetected," he said.

"It was a fake but could have been real and that is a cause for concern. It was very much the same story at Gatwick and Southampton.

"What I did find staggering is the fact that we only took three flights and every time the system failed."

Researchers for the show, to be screened on ITV next week, were also given airside jobs without references being checked.

The revelations follow the arrest last week of a man who attempted to smuggle a gun on a RyanAir flight from Stockholm to Stanstead.

"The secretary of state is extremely concerned about the allegations," a spokesman at the department of transport said after the meeting between Darling and BAA chief executive Mike Hodgkinson.

"This should never have been allowed to happen."

Shadow home secretary Oliver Letwin called for vigilance.

"We are all conscious of the need to maintain the utmost vigilance. It sounds like these are significant security lapses. I think we need to hear from ministers what they intend to do about it," he said.

A spokesman for BAA said the allegations were being taken seriously.

"Improved security measures have been introduced since September 11 with a greater police presence and additional searching of passengers and baggage," he said.

"We keep our security under constant review and we are actively seeking to improve security processes through new technology, working with government and research agencies."

The operator has held discussions with the government on installing a profiling system, in which travellers who do not conform to the details kept of a "normal" passenger are checked. These people are identified by such differences as body language and appearance.

"It's very difficult to build a profile to identify bad cats - it's easier to draw up a profile and say 'That's what normality looks like," BAA director of security Ian Hutcheson told the Guardian newspaper.

"If you meet the profile, you'd be subjected to base level security. If you're profiled out, you'd be subjected to additional security levels."

"We have got to be aware of what the statutes require. We could never made a profile based on someone's nationality," he added.

However, civil liberties groups have argued that the system would never be perfect, with some passengers falling foul of the tests due to speech impediments or illness.

"If you can target so that you don't get endless false positives, that's obviously a positive step. But we're yet to be convinced that it's possible to do that. There's always a concern this kind of profiling can lead to some form of discrimination," said a spokesman for Liberty.

Hutcheson also suggested that the list of banned objects should be modified, after concerns that thousands of seemingly harmless objects, such as scissors and knitting needles, were being confiscated on a daily basis.

"You could turn anything into a weapon," he said, "You could use your bare hands to throttle someone. Are we going to chop people's hands off?"