A man, carrying what is believed to be a gun, entered the bank on the High St, Henfield, and demanded cash at about 2.30pm. The man took a substantial amount of money before walking towards the library.

Staff and customers, who were in the bank at the time, were shocked but otherwise unhurt.

A man contacted police to say that he saw a man, with a similar description, walking on the road near a public house in Woodmancote at about 6.50am on Tuesday.

Police have also been approached by people who believe they saw the same man in Henfield before the robbery. Police would like this man to come forward to eliminate him from their enquiries.

The robber is described as white, of small build with a dirty complexion. He was wearing dark trousers and dark shoes, a knee-length dark coloured coat with hood and a shoulder length bag across his chest.

When he entered the bank, carrying a gun and demanding cash, he was wearing white or transluscent gloves. It is possible that he discarded these gloves and anyone who may have found them are asked to contact the police.

DS Pierre Serra said: "Witnesses in the bank are shaken but otherwise uninjured. They, along with others witnesses, are helping us with our enquiries.

"Searches have been made by police dogs, armed police and the Force helicopter. Forensic evidence has been gathered from the scene and our investigation continues.

"I would urge anyone with information to contact police on 0845 60 70 999."