The family of a Belfast postal worker shot dead by loyalists have urged a coroner to order 12 one-time suspects to give evidence at his inquest.

Lawyers for Daniel McColgan's relatives have also asked that a Scottish-based author who wrote a book about the UDA - the organisation that murdered the 20-year-old Catholic in 2002 - be called as a witness.

The father-of-one was gunned down by a UDA gang as he arrived for work at a sorting office in the loyalist Rathcoole estate in the Newtownabbey area of north Belfast.

At a preliminary hearing at Belfast Coroner's Court ahead of the scheduled inquest in March, barrister Andrew Moriarty, representing the McColgan family, told Northern Ireland's senior coroner John Leckey that he would like to see the 12 suspects appear in the witness box.

No-one has ever been convicted for the sectarian murder.

In a submission to the coroner, Mr Moriarty referred to press reports written in the years after the killing referring to the number of suspects police had arrested and questioned.

"It would be appropriate to have such persons called," he said.

But Mr Leckey expressed doubts about the request.

He said press reports did not constitute evidence and stressed that it was not the coroner's job to quiz suspects on alleged involvement in murder.

"I don't carry out a police investigation," he said.

Mark Robinson, representing the PSNI, also questioned the proposed course of action.

"This is not a re-opening of the police investigation," he said of the inquest.

Mr Leckey told the court he had asked the senior detective who investigated the murder at the time to prepare a statement for the inquest.

The coroner said he hoped the document prepared by now retired senior investigating officer Roy Suitters would cover the police's involvement with the 12 suspects - therefore negating any requirement to call them to give evidence.

He noted that transcripts of police interviews with the individuals were also available in PSNI documents disclosed to the next of kin.

A definitive ruling on the submission was not made and the issue is set to be raised again at a future preliminary hearing.

Mr Moriarty later asked the coroner to also consider adding the author Ian S Wood to the inquest witness list.

Mr Wood, an Edinburgh-based writer, penned Crimes of Loyalty: A History Of The UDA, which was published in 2006.

A section of the book refers to Mr McColgan's murder and the family want the author to give evidence on what his investigations had uncovered.

Again Mr Leckey questioned the worth of the exercise.

"The standard response from journalists is that they will not compromise their sources," he said.

Mr Robinson said that the author had already been interviewed by police and the transcript of the questions and answers had been disclosed to the court.

He questioned what additional evidence Mr Wood would provide.

"If pressed on detail he may say he wouldn't identify his sources," said the lawyer.

Mr Robinson added that if Mr Wood did recount conversations he had with others about what happened that would constitute hearsay evidence - which would be of limited use.

Mr Leckey said he would ask Mr Suitters to cover the claims made in Mr Wood's book in his statement to the court.

The coroner again deferred making any decision on Mr Wood's inclusion on the witness list to the next hearing.

Mr Moriarty also requested police reports on the history of the two guns used in the killing.

Mr Robinson said he would be in a position to indicate whether those reports could be disclosed in one week's time.

The coroner said he would also like Mr Suitters to cover the background of the weapons in his statement.

With Mr Leckey relying on the retired detective to compile a "comprehensive" submission, he expressed concern when Mr Robinson indicated there may be an issue that could impact on Mr Suitters' ability to access case files.

The lawyer explained that security clearance of retired officers lapsed after a certain time and, if that was the case with Mr Suitters, he would currently be unable to read sensitive documents related to the murder.

Mr Robinson said he would make enquiries to establish the position with Mr Suitters' clearance.

But he cautioned that if an issue did emerge it could potentially impact on the timetable.

Mr Leckey said he was keen to hold the inquest as soon as possible as he was mindful Mr McColgan's mother was in poor health.

"I'm concerned about the health of Mr McColgan's mother and she wants the inquest held," he said.

Legal representatives will convene again for another preliminary hearing in Belfast on March 20 to address all the outstanding issues.