SPECIALIST underwater robots with sonar will scour a river today near to where a missing Scots teenager was last seen.

A SARbot Remote Operated Vehicle is to be deployed along a stretch of the River Forth as part of efforts to trace David O'Halloran, 18.

It comes as Mr O'Halloran's father, Alan McInnes, is due to make an appeal for information at a press conference today.

Witnesses last saw the maths and education student from Kilmaurs, Ayrshire, who attends Stirling University, crossing Henderson Street, in Bridge of Allan, near the fast-flowing Allanwater river, a Forth tributary, at 2.19am on January 18.

He was wearing a T-shirt, shirt and jeans in temperatures of minus 4C. David, who also worked at KFC in Stirling, got into a cab at the Dusk nightspot in Stirling, around 12.30am on January 18, after a night out.

His family have since learned he had been playing drinking games before he left his accommodation. David's mother Donna said:"The police have arranged for representatives from SARbot UK to assist.

"We would once more like to thank you all for your wonderful support. We want to get this message out to youngsters all over the world. There are many lessons to be learned from David's tragedy. Let's make our youngsters more aware."

SARbot search and rescue submarines have sonar imagery capabilities and a grabber to pull drowning victims to the surface.