The body was discovered in the garden of an unoccupied house on the outskirts of Castlebar late on Friday night.

Gardai believe they have identified the man and have sealed off a nearby apartment in order to carry out a detailed forensic examination.

A post-mortem held yesterday failed to establish how the man died. Although he has not yet been named, gardai believe he was in his 50s and hailed from eastern Europe.

It is believed that the failure to establish the cause of death was due to the decomposed state of the body. Gardai believe the man may have died several weeks ago.

The body was found at the back garden of a house in the Saleen area, about one mile from Castlebar on the Ballinrobe Road.

The man is the third eastern European to be killed in Ireland this year. A Lithuanian man died from head injuries following an assault in Dublin on 7 January, while a Latvian man was stabbed to death at his home in Dublin on 15 February.