Pictures apparently showing a group of trespassers posing at the top of Europe's tallest building after breaking into the unfinished skyscraper have appeared online.
The series of night-time images, said to be taken at the summit of the 1016ft (310m) Shard in central London, were posted on the web blog of a US student who claims to have slipped past security with two friends.
One image shows a man sitting in the cab of a crane at the top of the giant glass skyscraper, which is due to be completed in June, while others show the trespassers climbing ladders running up the side of the towering structure.
A number of aerial views of central London apparently taken from the top of the Shard were also posted.
Bradley L. Garrett, who uploaded the pictures on his blog named Place Hacking, claims just one security officer was guarding the £435m building when he broke in.
He said: "As of December 2011, the Shard claimed the title of 'tallest building in the European Union', stretching 310 meters into the clouds from London Bridge.
"It has also been said that is it the most secure site in the city outside of the 2012 Olympic Park. I have never measured the building so I can't testify to the validity of the first claim but I'm happy to respond to the second, as usual."
Describing how the men broke into the construction site the blog continues: "We waited for the guard to finish his current round and go into his hut.
"It took a few minutes of lingering before the walkway was clear of people - we grabbed onto the scaffolding pipes and swung off the bridge.
"Hanging on the freezing pipes, we pulled ourselves on top of the walkway and laid down out of view, waiting for a reaction in case anyone had seen or heard us. It didn't seem so.
"Staying low, we then descended the other side of the scaffolding, right behind the security hut where we could see the guard watching TV, not the cameras.
"Quickly, we scampered across the yard and found the central stair case, again pausing to see if there was any reaction from the yard, phones ringing or doors opening. It was silent."
Describing the moment they reached the top of the skyscraper, the blog adds:
"We were so high, I couldn't see anything moving at street level. No buses, no cars, just rows of lights and train lines that looked like converging river systems, a giant urban circuit board."
Scotland Yard said it had not received any complaints about the alleged break-in.
The Shard has become the tallest building in the European Union and the 45th tallest in the world.
It surpassed the previous record-holder for the capital, One Canada Square at Canary Wharf, which stands at 235 metres or 773ft and was completed in 1991.
The Sellar Property Group is the developer behind the project.