Terence Wheelock (20), of Summerhill, Dublin, was found unconscious in a cell at Store Street garda station last June.

He never regained consciousness and later died at the Mater hospital on 16 September 2005.

According to the Garda Press Office, Wheelock was found unconscious and lying against a side wall with a ligature tied around his neck. The ligature, which was a cord from his tracksuit trousers, was secured to a small metal buzzer which was countersunk into the wall.

Wheelock's family has questioned the circumstances of his death and claims he was mistreated while in custody.

Among a series of questions raised by legal representatives for the Wheelock family is why the name of the arresting garda was altered subsequent to Wheelock being arrested.

On Section B of the custody record, the name of a second garda is added to the document and the garda who was initially recorded as the arresting officer is crossed off.

Speaking to the Sunday Tribune, the solicitor for the family, Yvonne Bambury, described the alteration to the custody record as "unprecedented". She said that as a solicitor working in the criminal justice area for 20 years, she had "never ever seen this happen before".

Bambury said that gardai had failed to answer why the alteration was made to the document. She added that gardai had also yet to adequately explain why the cell in which Wheelock died was renovated before an internal garda investigation into the youth's death could examine the scene.

The buzzer to which the cord was tied was flush with the wall and the only means by which a person could have attached a ligature to this would be by tearing away at the concrete around the fixture. Bambury said that photographs taken of Wheelock's body after his death show no indication of the trauma to his fingers that would have been caused by scraping the concrete with this fingertips. As the cell was renovated, the family do not know if there was pre-existing damage already done to the fixture, in which case it may not have been suitable for detaining arrested persons.

The family spent several months seeking to have the dead man's clothes returned to them for independent forensic analysis, but the state would not release them. Earlier this month, the state informed the family that it would allow an independent forensic specialist to travel here from the UK to carry out tests on the clothing at the forensic state laboratory.

An internal garda report has been sent to justice minister Michael McDowell in relation to the death in custody, but the family's legal representatives have not been allowed access to this. Bambury said that, to date, all questions put to the gardai in relation to the specifics of the circumstances of Wheelock's death have been met with "a blue wall".

Wheelock, along with three others, was arrested on 2 June last year for an alleged offence under Section 112 of the Road Traffic Acts (unauthorised taking of a vehicle). The vehicle, a disabled driver vehicle, had been stolen sometime earlier in the Donnybrook area.

When recovered, some 5,500 of damage had been done to the car, including the destruction of a mechanical lift required for the driver to access the vehicle. The three others who were also arrested in relation to the alleged offence were later charged, according to the Garda Press Office.