A BUTTERFLY once pronounced extinct in the UK has been seen in record numbers this year, according to conservationists.

There were over 10,000 adult large blue butterflies in the south of England - the largest concentration of the species known in the world.

Conservationists said the findings contradicted widely-reported warnings that 2016 could be the worst year on record for British butterflies.

In total more than 250,000 eggs were laid by large blue butterflies this summer.

The rare butterfly, which was reintroduced to the UK in 1984, is the only UK butterfly species listed on The International Union for Conservation of Nature as an endangered species.

Professor Jeremy Thomas, chairman of the Joint Committee For The Restoration Of The Large Blue Butterfly, said the numbers of the butterfly were its highest for 80 years.

He said: "The success of this project is testimony to what large scale collaboration between conservationists, scientists and volunteers can achieve.

"Its greatest legacy is that it demonstrates that we can reverse the decline of globally-threatened species once we understand the driving factors."