UPDATE 2-Sixteen migrants found in sealed container on ferry to Ireland, all in good health

(Recasts first sentence with origin of migrants, details on migrants, statement by police)

DUBLIN, Nov 21 (Reuters) - The crew of a passenger ferry travelling to Ireland from France discovered 16 migrants of Middle Eastern origin stowed aboard in a sealed trailer on Thursday, all of them in good health, Irish police said.

The 16 men were found during a routine inspection on board the ferry while it was travelling from the French port of Cherbourg to Rosslare in southeast Ireland, a spokesman for the vessel's Swedish operator, Stena Line, said.

Police said they believe all the migrants are adults, but are still seeking to confirm the age of one man who may be a juvenile.

Staff on the ferry, with the assistance of the lorry driver, opened the trailer unit after the discovery and the men were brought to a private lounge where they received immediate medical and welfare care, police said in a statement.

Immigration officers began processing the men under immigration legislation after the vessel arrived in Ireland at around 1440 GMT, it added.

"This has been a traumatic experience for these men and they are being treated with sympathy and compassion," the statement said.

Police are examining the truck, which they said is owned by a local Irish based-company. The owners and the driver, a male in his 50s who has been a resident of Ireland for over 25 years are co-operating fully with the investigation, police said.

On Oct. 23, the bodies of 39 people, all believed to be Vietnamese migrants, were discovered in the back of a refrigerated truck near London. Two people have been charged in Britain and eight in Vietnam over the deaths.

Dutch authorities on Tuesday found 25 migrants stowed away on a cargo ferry bound for Britain shortly after it left the Netherlands. (Reporting by Conor Humphries and Padraic Halpinin in Dublin Editing by Gareth Jones and Matthew Lewis)