1,500 passengers on board an Irish Ferries cruise ship were held off-shore for over an hour tonight following an alert over a "medical issue".

The Ulysses, which had been travelling from Holyhead to Dublin, had been due to arrive at around 5.30pm when it received the request from Holyhead Port Authority.

The ship remained at sea until the all-clear was given to allow all 1,555 passengers to disembark at 6.30pm.

An Irish Ferries spokesperson explained the incident:

“Our ship, the Ulysses, was arriving into Dublin Port, and we were asked by the port authorities in Holyhead to hold our passengers on board, and not discharge them. Apparently, there was some situation being investigated on the UK side.

“It’s normal procedure that we would act on that request, so we acted on it.

"Just about an hour later, at 6.30pm, we got clearance to release the passengers. We let them off on their way and the vessel concerned is now back in normal service, on its way back over to Holyhead.”