Cameron says morning swim helped with G8 Syria talks

A dip in the icy waters of a Northern Irish lake proved the ideal tonic before a day of tough talks with G8 leaders on tax evasion and the Syria crisis, British Prime Minister David Cameron said on Tuesday.

Cameron told a press conference on the banks of picturesque Lough Erne that he had had a swim in the lake that same morning, before the second and final day of the summit.

"As for how to prepare for a hard day's negotiation I can recommend a swim in the lough. That's what I did," Cameron said when asked if he had been for a dip.

"It certainly wakes you up in the morning and gets you going for a hard day of chairing these meetings."

The G8 leaders discussed the conflict in Syria in talks that pitted Russian President Vladimir Putin against Western nations, and also sealed a deal on tax evasion.

But Cameron -- who has previously been pictured before big events going jogging to keep fit -- said the world would not get to see his swimming exploits.

"I have the photographic evidence but I'm not going to share it with any of you," he told the press conference, to laughter from the assembled journalists.

Later he revealed that there was a surprise at the bottom of the lake, a sweeping expanse of water ringed by emerald hills near the town of Enniskillen.

"Now #G8UK is over I can reveal a bomb was found in Lough Erne," Cameron tweeted.

"It was American from WW2. Apparently they had a practise mortar range here!"