The trial of a man charged with murdering teenager Marioara Rostas six years ago has heard he told a friend of his that Ms Rostas was shot because she was a witness.

Alan Wilson, of New Street Gardens in Dublin, has pleaded not guilty to the murder of the 18-year-old girl at a house on Brabazon Street, The Coombe in Dublin between 7 and 8 January 2008.

The jury was told that 35-year-old Mr Wilson ordered a friend to help him remove Ms Rostas' body from an upstairs bedroom and bury her in a shallow grave in a forest in the Dublin/Wicklow mountains.

The court was also told that Mr Wilson ordered his friend Fergus O’Hanlon to clean the murder scene with bleach and ammonia.

Senior Counsel Sean Gillane also said that Mr O'Hanlon will testify that Mr Wilson warned him not to return to the place where Ms Rostas was buried and told him "you never saw what you saw".

The Central Criminal Court heard today that Ms Rostas was begging with her family in Dublin city centre on 6 January 2008 when a man in a Ford Mondeo car beckoned to her, mentioned McDonald's, gave her brother €10 and drove away with her.

Her family never saw her alive again.

Mr Wilson admitted through his counsel today that his car was a Mondeo, but denied he was driving it at the time.

The prosecution alleges that Ms Rostas was shot four times in the head at a house in Brabazon Street where Mr Wilson's sister Maxine lived with his friend Mr O'Hanlon.

The court heard that Mr O'Hanlon saw Mr Wilson coming down the stairs holding a firearm, that Mr Wilson told him he wanted to show him something, brought him upstairs, showed him a corpse and told him "she was a witness".

Senior Counsel Mr Gillane said Mr O'Hanlon will give evidence that Mr Wilson told him to take off Ms Rostas's shoes and clothes. A pillow was put over her head, her legs were tied with a sheet, she was rolled in plastic and her remains were placed in a large bag, which Mr Wilson carried to the boot of a Mondeo car.

The court was also told that Mr O'Hanlon will also testify that the two men drove to the Dublin Mountains and that he carried a shovel while Mr Wilson carried Ms Rostas's remains up a steep incline.

The jury heard that Mr Wilson appeared to be looking for a grave that had already been dug, but when he could not find it, they buried MS Rostas in the shallow grave - in which she was found four years later.

The jury was also told that Mr Wilson told Mr O'Hanlon to clean the room at Brabazon Street and he did so for a number of days - supervised by Mr Wilson - and that Mr Wilson also warned him never to return to the Dublin/Wicklow mountains where Ms Rostas was buried and told him: "You never saw what you saw".

Almost four years later the court heard Mr O'Hanlon told the gardaí he had information about the case and was prepared to help in the search. He subsequently identified locations in the mountains.

The trial is expected to last three to four weeks.