The family of Nico Meli plan legal action against health bosses

Nico Meli, 35, from Aspley, Nottingham, was attacked by Stephen McGowan, 32.

McGowan was ruled unfit to be tried for murder and sent to a secure hospital after a jury ruled he was responsible for the killing in October 2003.

The Nottinghamshire Healthcare NHS Trust said it had launched a "rigorous internal review" after the attack.

Mr Meli was said to have befriended his killer after a chance meeting while out shopping.

Occasionally people with mental health problems become unpredictable Nottinghamshire Healthcare NHS Trust

Later a relationship developed between McGowan and Mr Meli's mother.

Mr Meli was stabbed at his mother's home in Beechdale.

His girlfriend, Tanya Wood, who had a son - now aged 10 - with Mr Meli, said health chiefs should have alerted them to McGowan's condition.

He was assessed in 1998 as having a personality disorder under the Mental Health Act.

Tanya Wood had a son with Nico Meli

But it was not deemed treatable and so he was not detained under the act.

He also had brain damage because he had been involved in road accidents.

Ms Wood said: "I wished they would have helped me in some way to protect Nico, to let us know he (McGowan) was violent and we could have done something to protect him.

"I will never forgive them for leaving us like this, for ruining our lives - our lives have completely changed now.

"I don't think I can ever cope with losing him, especially the way he died."

A statement from the Nottinghamshire Healthcare NHS Trust said: "Occasionally people with mental health problems become unpredictable...when that has tragic outcomes steps are taken to see what can be learnt."

It added: "These events in Nottingham have been subject to a rigorous internal review."