A gang of thieves stole rhinoceros horns worth €500,000 from a National Museum of Ireland storage facility in Dublin last month.

The raid took place on 17 April when a group overpowered and tied up a security guard. The guard, who was not injured, managed to free himself and notify the police.

A statement from the National Museum of Ireland said: “The stolen rhinoceros heads have a total of eight horns that have probably been taken to supply the illegal trade in powdered horn that is used in traditional medicines in the Far East. Their price is based on weight, and the total amount stolen could have a street value in the region of €500,000.”

The stolen specimens were moved into storage last year following a spate of thefts from museums across Europe. There are no rhinoceros horns on display in the National Museum of Ireland’s natural history building.

Nigel Monaghan, a keeper in the museum’s natural history division, said the organisation was conducting a full security review following the theft.

The UK Border Agency recently warned UK museums that gangs regarded them as easy targets, highlighted by an attempted daytime theft of a rhino head from Norwich Castle in 2012.

Museums with rhino horns in their collections are being encouraged to submit samples to a UK-wide rhino DNA database that is being set up by Science and Advice for Scottish Agriculture in Scotland with funding from the Department for Environment, Food and Rural Affairs.