A 19-year-old woman who failed to appear as a witness in a murder trial has been warned by the Central Criminal Court that she could face significant time in jail.

Stephanie Tuite is the former girlfriend of Daniel McDonnell who last week was jailed for life for the murder of 16-year-old Melanie McCarthy-McNamara.

She was brought to court after a warrant was issued for her arrest last Thursday.

Mr Justice Paul Carney told Ms Tuite, from Glenahsane Crescent in Tallaght, that she was an important witness in a very serious trial and that he had evidence that she had "gone to ground in a very deliberate fashion".

The judge said she could have threatened the viability of a very serious case involving a 16-year-old girl who was shot dead.

He said what was being alleged was a very grave contempt of court and she could face a significant period of imprisonment.

He adjourned the case until Thursday and to allow her time to seek legal advice, adding: "You are going to need it."

McDonnell’s trial heard he had written a letter to Ms Tuite while in custody in which he spoke about the killing of Ms McCarthy-McNamara.

He wrote that the shooting would not have happened if he had known she was in the car.

The letter was intercepted by prison authorities.

Ms McCarthy-McNamara died after she was shot in the head while sitting in a car with her boyfriend and another man in Tallaght in February 2012.