The 32-year-old mother of four is likely to be prosecuted after the phone was recovered during a search of her cell last week, the Sunday Tribune has learned.

Mulhall is serving a 15-year jail sentence for the manslaughter of her mother's boyfriend, whose dismembered corpse was found in the Royal Canal in Ballybough, Dublin.

She and her younger sister, Charlotte, beat and stabbed Farah Swaleh Noor to death in March 2005 before cutting his body into pieces and dumping it in the canal.

Linda Mulhall admitted to gardai that she had cut the 38-year-old's head off and took it by bus to Tallaght, where she buried it in a busy park. She later returned and dug up the Kenyan's head before moved it to another field and smashing the skull with a hammer.

A jury found Linda Mulhall guilty of Noor's manslaughter on the basis that he had made unwanted sexual advances towards her before the two women attacked him. Charlotte Mulhall, 23, was convicted of Noor's murder and is serving a mandatory life sentence.

Linda Mulhall regarded her 15-year jail term as excessive and her appeal will be heard in December. However, her hopes of early release were dealt a major blow last week after the mobile phone was found in the mattress of her bed in the Dochas women's prison in Mountjoy.

Gardai have been informed of the discovery and will be arresting Mulhall for questioning. The possession of a phone in prison is regarded as a serious offence and carries a maximum sentence of five years' imprisonment.

Linda Mulhall has already been the subject of internal prison disciplinary proceedings after she was found with alcohol earlier this year. A package had been thrown over the jail's perimeter wall and she was discovered trying to take it to her cell.

A prison source said:

"Linda has been consistently causing trouble in jail and is a handful. She will probably have to go to court to answer for her conduct and a fiveyear sentence is possible. She will be hoping for a fine, though, but it is hanging over her."