Roman coins minted almost 1,700 years ago have gone on display in Rickmansworth, 35 years after they were found during excavations in the area.

The coins were dug up during the excavation of Heronsgate reservoir, off Stag Lane, between 1977 and 1978 but they only went on display this week at the Three Rivers Museum in Basing House after decades in storage.

Around 4,350 low value coins were found along with a number of clay pots during excavations by the Rickmansworth Water Company, now Affinity Water, and were sent to the British Museum for evaluation.

The museum identified them as being of low value and returned them to the water company which shared 10 coins with each member of staff, the rest were placed into storage at the company’s office.

There they remained until earlier this year when the company’s retired managing director Robert Simpson found his coins while clearing his attic.

He said: "It was a very exciting find but they weren’t worth very much, all members of staff who wanted them had 10.

"I was looking through my belongings and found them, I started wondering where the rest of them were so I contacted Affinity which searched around the archives and found them, which was great.

"I contacted Barbra (Owen, Three Rivers Museum chairman) to see if she wanted them for the museum and she said yes."

The coins are now on permanent loan to the museum.

Les Mead, vice-chairman of the museum and council chairman, said: "We think it is a really great thing they have offered to the museum.

"It is a very welcome addition before our heritage day next month."

The coins were among those commissioned by Emperor Constantine between 330 and 345 AD to celebrate the founding of the new city of Constantinople (now Istanbul) on the ancient Greek city of Byzantium.