'Because of the weather earlier this year I didn't really get to have a proper look at it,' said Mr O'Sullivan, of Dagenham, Essex.

'Then, last week, as I was sunbathing in the back garden I poked my head over the pond and there it was swimming towards me.

'It was astonishing. I could easily make out from the markings two eyes, a nose and a mouth. I thought I was suffering from sunstroke.'

Carp have long been known to carry markings which can look like a human face, but actually seeing one is rare.

As a result, Mr O'Sullivan's fish is now said to be worth an estimated £40,000.