The cannonball, advertised as 100% genuine, had a starting price of £5,000.

An individual trying to sell what was claimed to be a piece of shot from the Mary Rose on Internet auction site eBay has had 14 cannon balls confiscated as part of a joint operation by the Receiver of Wreck and the Mary Rose Trust.

The move came after the trust received a tip off that someone was attempting to sell a cannon ball on eBay for over £5,000 as a genuine 500-year-old artefact from the Mary Rose.

"We are delighted that the Receiver of Wreck took swift action to investigate the claim that this iron shot was from the Mary Rose," said Mary Rose Trust Chief Executive, John Lippiett.

"There should not be any artefacts from the Mary Rose in private hands apart from a few curios made from Mary Rose timber recovered in the 1830s and we would always like to be alerted to any fraudulent or illegal sales."

A contemporary illustration of the Mary Rose. © Pepys Library, Magdalene College, Cambridge.

Alongside the Receiver of Wreck, the trust used the opportunity to issue a warning to those tempted to buy objects listed as having come from the wreck of the Mary Rose.

Such items, they say, are highly unlikely to have come from the Mary Rose and if they are they will have been acquired illegally.

"We are relieved that the shot turned out to be nothing to do with the Mary Rose," added John Lippiett, "but are not pleased that the vendor tried to pass them off as genuine and even used a photograph taken without authority from our website."

One of the many genuine artefacts to have been found on the Solent sea bed - a leather shoe, discovered earlier this year. Photo: David Prudames. © 24 Hour Museum.

The Portsmouth-based Mary Rose Trust, which organised the raising of the Tudor wreck in 1982 and is still working on conserving it, was alerted to the sale by a diver who worked on the original excavation.

Believing the items must be from another source or have been acquired illegally, staff at the trust passed it on to the Receiver of Wreck, who under the Merchant Shipping Act 1995 has powers to investigate such matters and seize material.

The Mary Rose is one of 55 sites in the UK that are designated under the Protection of Wrecks Act 1973 and therefore any unauthorised interference with it is an offence.

Working alongside eBay and the Hampshire Police Marine Unit, the Receiver of Wreck was able to track down the vendor and confiscate 14 cannonballs from their premises.

The Mary Rose Trust has undertaken a series of dives on the wreck in recent years, bringing up a series of fascinating finds. Photo: David Prudames. © 24 Hour Museum.

All of them were later inspected by Curator of Ordnance at the Mary Rose Trust, Alexzandra Hildred, who confirmed they had none of the features found on shot from the Mary Rose.

Enquiries into the real origins of the shot are now being conducted by the Police Marine Unit, though it is believed they are 18th or 19th century and were recovered on the shores of the River Hamble.

"This joint operation shows that the Maritime and Coastguard Agency is willing and able to act on credible information received in relation to offences regarding illegally held wreck material," explained Receiver of Wreck, Sophia Exelby.

"Although these cannonballs did not ultimately come from the Mary Rose, the principles of investigation and enforcement are the same and will be applied to any other such cases which arise."