The mother of Belfast teenager Noah Donohoe who was found dead in a storm drain last year has called for a "thorough investigation" into his disappearance and death.

Fiona Donohoe expressed her gratitude to the hundreds of people who joined her yesterday evening outside the gates of Stormont, where she placed a message demanding answers over what happened to her son.

A coroner is investigating lines of evidence after the 14-year-old's body was recovered near the M2 motorway in June, six days after he went missing in the north of the city.

A coroner's representative told the brief review hearing at Laganside courthouse on 2 November that footage surrounding his disappearance had been reviewed and the police file was almost complete.

Barrister Declan Quinn said at the time: "The police are investigating health and safety issues that may arise in this inquest."

Ms Donohoe told those gathered outside Stormont that she was looking for the truth about what happened to her son.

She told the BBC she was not at liberty to comment on the current police probe into Noah's death.

"All I want is for an investigation, a thorough investigation for my son, for every child in Northern Ireland," the broadcaster quoted her as saying.

"Every parent should know their child should be able to go out and come home safely."

The PSNI said last year they believe Noah entered the drain in the Northwood Road area of north Belfast.

He had cycled to the area from his home in south Belfast and, shortly before he went missing, was seen with no clothes on.

Prior to that he was seen falling off his bike in Shore Road.

His disappearance prompted a major search operation, with hundreds of people from across Belfast involved.

Plans to hold the full inquest in January should be postponed and another review hearing scheduled instead, due to the nature of preliminary matters arising, family lawyer Niall Murphy said in November.

He said matters surrounding the disclosure of evidence and inquiries into health and safety and whether they may impact on progress should be better understood by then.

Noah's body was found by specially trained police officers between two drain access points within a section of storm drain tunnel running under the Translink public transport cleaning facility access road.