As McLaren team boss Ron Dennis explained at the British Grand Prix last weekend, there is a clear dividing line between what is generally considered acceptable and what is evidently illegal.

"I remember with great amusement locking another team's aerodynamicist, who was measuring and photographing parts of our bodywork, into the back of our truck," Dennis recalled of one past incident.

"And you could say that was over the limit.

"Equally, many photographers are commissioned to take detailed photographs of other people's cars -- and we take detailed photographs of other people's cars," added Dennis.

"And that is probably within the accepted practices in grand prix racing.

"There are unwritten limits to which everybody should adhere and clearly these (latest allegations) exceed all previously known occurrences."

NO SURPRISE

The case involving McLaren's chief designer Mike Coughlan, suspended last week after a house search found a significant quantity of confidential Ferrari technical information, has been the talk of the paddock.

There have been allegations of sabotage, denied by former Ferrari engineer Nigel Stepney who has also rejected suggestions that he and former Benetton colleague and fellow-Briton Coughlan were acting together.

The courts will unravel the full story but, whatever the outcome, few if anyone in Formula One will have been surprised by data leaking from one team to another.

"You cannot stop it. As long as human beings are around, it will always be there," former champion Niki Lauda said of paddock espionage.

"These things happen, in big car manufacturers and everywhere. It's logical."

The last such incident happened in 2002 when Ferrari took legal action against two of their engineers who had moved to Toyota, whose subsequent car aroused suspicions.

Earlier this season, Spyker principal Colin Kolles presented a Red Bull document to try and demonstrate the illegality of that team's car.

Formula One is a sport where people have been known to start rumours just for fun, to see how long it takes before the whispers come full circle. There is a constant exchange of information.

At the Canadian Grand Prix some years ago, then team boss Eddie Jordan related how he had been given a digital photograph of a race engineer's sheet taken by somebody peering down from the Paddock Club above.

The Paddock Club is an exclusive area reserved for VIPs, sponsors and special guests.

GARDENING LEAVE

In those days, teams covered up their race cars and erected screens in front of the garages to keep out the photographers' lenses.

But there is little teams can do when designers and top technical staff are headhunted other than impose a period of 'gardening leave' before they start their new jobs.

"You cannot un-invent things," said Dennis. "People move with all the knowledge and inevitably that knowledge is going to appear, sometimes with great perfection and accuracy, on other grand prix cars."

The classic case of that occurred in 1977, when ex-Shadow employees founded Arrows.

Their car was built in a mere 60 days but hit trouble when Shadow chief Don Nichols claimed the A1 was nothing more than a copy of his DN9 -- both designed by Tony Southgate.

The High Court found in favour of Shadow and Arrows had to come up with a replacement, which they did without even missing a race.

Perhaps the most bizarre case, however, was one that apparently involved real spies.

In 2001, Renault technical director Jean-Jacques His revealed that the company's system had been hacked into and final designs for that year's Formula One engine tampered with.

The Frenchman blamed former members of the East German Stasi secret police.