London Olympic officials worried about three notorious British pranksters

Olympic chiefs are drawing up extra security measures amid fears that this summer's London Games may be targeted by three of Britain's most notorious pranksters.

From infiltrating a Manchester United team photo to dashing onto the podium at a Formula One race, Karl Power, Tommy Dunn and his son Tommy Jr. have gained a certain level of fame for pulling off a number of daring pranks at some of the United Kingdom's most high-profile sporting events.

Now, in the wake of scenes at last weekend's University Boat Race between Oxford and Cambridge, where a protestor swam into the River Thames and caused the race to be restarted, the London organizing committee is desperate to avoid any embarrassment in front of the eyes of the world in four months' time.

[ Also: Dwyane Wade thinks NBA players should be paid for playing in the Olympics ]

"It's not likely to be a well-orchestrated campaign through Twitter or websites," said British Olympic Association chief Colin Moynihan. "It is likely to be someone similar to the [Boat Race] idiot who causes major disruption. You can never completely remove [the threat] but you can do everything possible to protect the interests of the athletes by minimizing it."

According to a source close to LOCOG (London Organizing Committee of the Olympic Games), the names of Power and both Dunns were raised at a high-level Olympic security meeting this week.

"The Boat Race incident has been a wake-up call for everyone," the source said in a telephone conversation with Yahoo! Sports. "We are aware of the threat posed by those three, others like them, as well as protestors. Measures will be taken."

And they should be, according to one of the Dunn's friends.

"Get ready for something special at the Games," read an instant message sent to Yahoo! Sports from the friend. "The boys are ready. It will be their best one yet."

Power's first stunt, assisted by then elder Dunn, took place in 2001 when he managed to walk onto the field ahead of a Manchester United Champions League game. Clad in full team uniform, Power lined up with the United side for the official team photo at Munich's Olympic Stadium, having been able to enter the arena by posing as a member of a television crew.

Months later he walked onto the field during a crucial stage of an international cricket match between England and Australia at Leeds' Headingly Stadium. After hiding in a toilet by the players' locker rooms, Power, clad in full cricket gear with pads, gloves and a helmet, strode onto the field of play and made his way toward the batting area. Halfway there he stopped, removed his helmet to reveal himself and pulled out a cell phone.

It wasn't until he removed his helmet that the crowd and television audience realized he was an imposter, not one of the England players, coming out to bat.

In 2002, Power and the Dunns left the crowd at the British Grand Prix bewildered as they dashed onto the podium, dressed in full race suits, moments before race winner Michael Schumacher was due to receive his trophy.

Later the same year, Power and Dunn Jr. found their way onto Center Court at Wimbledon before a match involving local favorite Tim Henman. The pair played a short game of tennis to the delight of a packed audience before running out of balls to use and leaving of their own accord.

The trio laid low for several years and was thought to have given up their mischievous ways.

[ More: David Beckham desperately wants to represent Great Britain but will he? ]

However, Dunn and his son resurfaced in 2010, managing to get past tight security at the England soccer team's hotel. They planted a bug in a meeting room that had been used by then-head coach Fabio Capello, and hoaxed former captain John Terry by asking him to sign an autograph to Wayne Bridge, an England teammate whose ex-girlfriend he was alleged to have slept with.

Power and the Dunns have close ties with several English newspapers, which have delighted in publicizing their antics over the years. Rumors are strong among members of the British media that the group may be planning its "most epic" stunt yet to coincide with London's hosting of the Summer Olympic Games.

While the trio's pranks have never actually interfered with a sporting contest itself – unlike the "Boat Race swimmer" – Olympic bosses would still be deeply embarrassed if such a breach took place this summer.

It is thought that events held in public areas, such as the marathon, the cycling road race and the triathlon are at greatest risk.

At the 2004 Athens Olympics, Brazilian Vanderlei de Lima was deliberately accosted and impeded by Irish protestor Cornelius Horan during the running of the marathon. The incident cost de Lima, who was leading at the time, around 20 seconds in lost time and he was later overtaken and finished third.

Other popular content on the Yahoo! network:
• Sex Pistols decline an invitation to perform at the Olympics closing ceremony
• Seven years after Katrina, University of New Orleans hoops still trying to recover
• Y! News: Mike Tyson on George Zimmerman: 'It's a disgrace he hasn't been shot yet'