The 25-year-old from Bangor vanished on February 27th, 2005 after attending a party at Ballyhalbert Caravan Park

The 68-year-old was arrested on suspicion of murder, assisting offenders, withholding information and preventing a lawful and decent burial.

The 25-year-old disappeared in 2005 and is assumed to have been murdered, but her body has never been recovered.

The Co Down woman’s family gathered at a memorial bench on the 20th anniversary of her disappearance.

The Bangor woman went missing on February 27th, 2005, and is believed to have been murdered but her body has never been found.

Miss Dorrian was 25 when she was last seen at a caravan park in Ballyhalbert, Co Down, in 2005