Lawyers for convicted serial killer Mark Nash told the Supreme Court his constitutional and human rights were breached by a delay in his prosecution.

They claim he should be entitled to damages for a 12-year delay in charging him for the murders of two elderly women in Dublin.

In April of last year, Mark Nash was found guilty of murdering two women in Grangegorman in Dublin in March of 1997.

He admitted the murders while being questioned about an assault on a woman in Roscommon during a garda interview in Galway five months later.

59-year-old Sylvia Shiels and 61-year-old Mary Callinan were stabbed to death while they slept in their beds.

Another man called Dean Lyons, who has since passed away, later admitted to the murders.

But a forensic breakthrough in 2009 led to the discovery of the DNA of the two women being found on Nash's jacket.

He was charged while serving a double life sentence for murdering two people in Roscommon in August 1997.

His legal team believes he is entitled to damages because of the delay in his prosecution.

His senior counsel, Hugh Hartnett, told the Supreme Court this morning that the developments that led to the forensic breakthrough in 2009 were available seven years beforehand - and the delay denied him his right to be tried within a reasonable time.