More than 16,000 UCD students yesterday received e-mails appealing for help in tracing the whereabouts of a 21-year-old student missing since last weekend.
The family of third-year horticulture student Richard (Richie) Wellwood from Abbeyleix, Co Laois, has also pledged a reward of €10,000 for information leading to his safe return.
Mr Wellwood was last seen outside the Abrakebabra restaurant on Westmoreland Street, Dublin, on Saturday last at 3.37am.
Yesterday Paul Wellwood, a brother of the missing man, told The Irish Times there were still no clues that might explain Richard's disappearance.
"The amount of friends that have contacted us in recent days is a reflection of Richie's amazing personality . . . he was not an unpredictable character," Mr Wellwood said.
Having begun his night in the student bar on UCD's Belfield campus to mark the start of mid-term break, Richard Wellwood went to Club M in Blooms Hotel in Temple Bar with four friends but became separated from them on exiting the nightclub.
He was wearing blue jeans, white Nike runners and a grey top with the hood pulled up at the time of his disappearance. He is 6'3" to 6'4", well built, with brown hair and brown eyes.
UCD students' union has now posted an appeal for information on its website and displayed posters across the campus. Last night union president James Carroll said that the union had e-mailed its 16,000 students in an effort to establish the whereabouts of Mr Wellwood.
Friends of the missing man were shocked at his disappearance, he added.
"It is very strange that on a Friday night, when everywhere is packed and there are a lot of people out on the street at that time, that anything suspicious could happen without an awful lot of people seeing it."
Anyone with information should contact Pearse Street Garda station on (01) 666 9000.