Comedian David Walliams, who is swimming the River Thames to raise money for Sport Relief, has been suffering from severe vomiting and diarrhoea.

But despite feeling unwell, he has rallied and set off on the third day of his 140-mile swim from Abingdon Lock this morning.

The Little Britain star passed through Days Lock at Little Wittenham after 2pm and is due at Shillingford Bridge, Wallingford, at 4pm.

According to Kimberley Williams, a spokesman for the Comic Relief, Mr Walliams has been struggling to cope with the river water.

Mr Walliams said: “I always knew there was a risk that taking in the water could cause problems but now it’s happened it has still hit me really hard.

“I was sweating in the night and have been to the toilet a lot this morning.”

But Mr Walliams’ spokesman Anna Capleton, who is part of a team following the comedian in a support boat, said: “David was really struggling this morning and he was being sick as he was swimming.

“But since then he has managed to keep some food down and is now making slow if good progress.”