A convicted child killer has launched a legal bid to halt an inquest into the death of a schoolgirl he was cleared of murdering.

The body of Arlene Arkinson, 15, from Castlederg, Co Tyrone, who disappeared after attending a disco in Bundoran, Co Donegal, in 1994 has never been found. Police are to launch new searches next month.

Robert Howard was found not guilty of her murder in 2005 but senior Northern Ireland coroner John Leckey said he would be calling him as a witness at the inquest into her death, adding that special measures would have to be taken for securing him.

But at a preliminary hearing in Belfast today, it emerged that Howard has lodged an appeal challenging a High Court decision allowing the inquest to proceed.

He is serving a life sentence in Frankland Prison, Durham, for the rape and murder of 14-year-old Hannah Williams, whose body was found at a cement works in Northfleet, Kent, in March 2002.

Fiona Doherty, a lawyer for the coroner, said: "A date has not been set yet but the Court of Appeal is fairly busy this term, but efforts will be made to ascertain whether that appeal can be expedited."

Last December, Mr Justice Seamus Treacy criticised the delay in holding the inquest, which was first ordered in 2007.

Howard's legal team argued that the hearing would be used to attempt to undermine his acquittal.

The inquest is due to get under way next September and is expected to last two months. But Ms Doherty said the Court of Appeal would have to hear legal arguments about whether it could go ahead.

There is also the potential that the inquest could be further delayed because of the ongoing police investigation.

Henry Toner QC, a barrister representing Arlene's family, said the grounds for Howard's appeal were fairly "thin".

He told today's hearing in Belfast: "I do not see it succeeding. That is my professional opinion."

He added that the family wanted the inquest to be held as soon as possible.

A Police Service of Northern Ireland barrister said fresh searches for Arlene's body were scheduled to commence in March.

He added: "It is difficult to give a precise timescale for the conclusion of those searches. It is anticipated that they would run through to the spring and possibly into the summer."

At this stage police do not believe their live investigation would be prejudiced by preparations for holding an inquest.

Arlene went missing 17 years ago after a night out across the Irish border in the seaside town of Bundoran. Police believe she was abducted and killed. The teenager was last seen in a car being driven by Howard.