The 25-year-old foreign national who was being questioned by gardaí about a serious assault in Dublin last night has been released without charge.
Gardaí say the investigation is continuing, and have appealed for witnesses to come forward.
The assault happened on Upper Gardiner Street just after 11pm.
A 31-year-old Polish man was attacked by a group of up to six people. Gardaí are trying to establish how the man ended up falling into a basement yard just off the street.
He received serious head injuries and is currently in a critical condition in the Mater Hospital.
