A naked man brought parts of central London to a standstill on Friday after he installed himself on a statue near Prime Minister David Cameron's office for nearly three hours.

He braved the November cold and gawking crowds to straddle the monument to Prince George, a 19th century military chief and one-time Duke of Cambridge, adopting various poses including balancing precariously on the prince's head.

Police were called to the statue on Whitehall, the street on which many government offices including Cameron's Downing Street residence are located, after reports that a man had climbed up and might have had a knife.

From midday to about 3pm, police cordoned off the area as they tried to persuade him to come down. Finally they got him into a police van, where he was detained under the Mental Health Act, police said.