Bear Grylls has said that his Christian faith helps him cope with claims his TV shows are faked.

The 40-year-old former SAS reservist told the Daily Mirror that he had been rocked by the criticism, which said was "99 per cent untrue".

He had to apologise in 2008 over his Born Survivor series, which gave the impression that he was abandoned in the wild but was actually shot over a longer period which included time in a motel.

His reality show The Island, which saw 13 men left to fend for themselves after basic survival training, was also criticised when it was revealed that a pool on the island had been lined with rubber to make sure that they had enough water to sustain themselves during the 28 days of the test. It was also found that two crocodiles had been released on to the island so that the men would have enough wildlife to sustain themselves and that at least two of them had worked with Grylls before.

Grylls said: "My Christian faith has been a very empowering and important part of my life for sure." Though he had made mistakes in the past, he said, his shows now had "100 per cent transparency".

In his new six-part series, Mission Survive (Friday, ITV, 9pm), Grylls takes eight celebrities including double Olympic champion Kelly Holmes, actors Emilia and Laurence Fox, singer Jamelia and former England rugby star Mike Tindall on a 12-day survival challenge into the Costa Rican rainforest.