Keith Towler said he was "truly honoured" by the appointment

A former director of crime reduction for the rehabilitation body Nacro, he has also been a member of the assembly government's New Deal taskforce.

Mr Towler said he was "truly honoured" and that "inside I'm a burning cauldron of excitement".

The post had been vacant since the death in January of Peter Clarke.

Education and Children Minister Jane Hutt announced Mr Towler's appointment, and he will take up the post in March.

This is a fantastic job and a fantastic opportunity but also a huge responsibility Keith Towler, new children's commissioner

He said: "This is a fantastic job and a fantastic opportunity but also a huge responsibility - and I will be doing a lot of listening as I start the job.

"Listening to children and young people, parents, teachers and everyone who has an interest in the rights of children.

"I will be championing the rights of children and my top priority is ending child poverty. There are things we are doing well and things we are doing not so well, and there is no room for complacency."

Ms Hutt said she wanted young people to have "the best possible start in life, so as they mature, they feel they have someone to champion their rights making sure that they are represented and treated fairly".

We would like the new commissioner to help get the message across that our children are not all hoodie-wearing monsters Andy James, Barnardo's Cymru

Candidates were interviewed by a panel of eight 14-19-year-olds from Funky Dragon - an organisation for young people - the Young Carers' Network, and the advisory groups in north and south Wales.

Ms Hutt and other AMs, as well as two members of the young people's panel, made the appointment.

She said: "I am confident that Keith Towler will be a great ambassador and representative for children and young people all over Wales".

He has spoken out in the past on issues such as child poverty, and his work with Nacro Cymru means he has a strong background in youth justice.

Following Mr Clarke's death from cancer, the commissioner's job had been filled on an acting basis.

Helen Mary Jones, chair of the assembly's children and young people committee, welcomed the appointment, but questioned the "exceedingly long and drawn-out process".

Before the official announcement was made, Andy James, the assistant director of children's charity Barnardo's Cymru, said: "We would like the new commissioner to help get the message across that our children are not all hoodie-wearing monsters, and the majority live positive lives."

In the past, Mr Towler has called for early intervention to prevent patterns of criminal behaviour developing, and warned against "demonising" the young.

Wenda Hatherley, the deputy director of children's services for NCH Cymru, said she was pleased the commissioner was "concerned to recognise the impact of portraying young people with positive images".