Roman coins collected by a numismatist will be auctioned off on July 3.

Proceeds from the specialist sale will go to the British Museum.

The late Kenneth Edwin Day, from Thames Ditton, was a leading figure in the Kingston Numismatic Society and keen Roman coin collector.

Auctioneer Morton and Eden will divide the coins between two sales and expected the collection to raise about £30,000.

The proceeds of both sales will be added to an acquisition fund set up so the museum can buy coins of significant to Britain and increase the accessibility of the national collection using new digital technology.

A spokesman for the British Museum said: “Ken decided some years ago that he would leave his collection to the British Museum, and we are delighted to have added some of his coins to the national collection for public benefit.

“It is a fitting testimony to his generosity and to a lifetime’s passion for Roman coins.

“Ken had a passion for sharing numismatic knowledge and would certainly have embraced the museum’s use of new digital media to make its collections more accessible to the general public.

“Ken’s generosity will ensure a continuing public legacy for his important contribution to numismatics in Britain.”

Mr Day’s collection is wide-ranging and includes a number of rare examples such as a denarius, which shows on the reverse a triumphal arch inscribed de Britann.

The coin commemorated Claudius’s invasion of Britain in AD43 and has an estimated value of £400-£500.

A gold aureus of Marcus Aurelius depicting the emperor as Caesar from AD139-161, with Mars the God of War on the reverse, is estimated to reach an impressive £800-£1,000.

Part one of the collection goes on sale at Sotheby’s on July 3 and 4.

It will be on public view at 45 Maddox Street W1, on Thursday, June 28, Friday, June 29, and Monday, July 2.