The imported fish, weighing 74lb and 62lb, are far larger than anything in British waters. An angler catching one would shatter the official carp record of 51lb 8oz.
On the eve of the coarse fishing season, Tony Wilkinson of Hawkhurst Fish Farm, in Hawkhurst, Kent, moved the pair of Chinese blue or snail-eating carp, a species not found in Britain, into a three-acre lake on his koi fish farm, and offered anglers a chance to catch them for pounds 40 a day.
Mr Wilkinson bought the carp for pounds 7,000 in a postal auction nearly three months ago from a batch of six imported from China in February.
However, his plan has been blocked by the Ministry of Fisheries because he has only an ornamental licence for the carp, which does not entitle him to let anglers fish for them.
Chris Yates, who holds the British carp record with a 51lb 8oz mirror carp caught from Redmire Pool, Hereford and Worcester, in 1981, said: 'I find it a little sad. If that is what people want, then fair enough, but I wouldn't want to fish for something like that.'
A spokesman for the British Record Fish Committee said any carp record claim would be discussed on its merits. The committee did not differentiate between species of carp.