An independent report has urged ministers to raise the age of criminal responsibility in Scotland to 16 and set up a new youth justice system for offenders up to the age of 21.

The work, commissioned jointly by the charity Action for Children and Bruce Adamson, Scotland's Children and Young People's Commissioner, also highlighted the lack of secure accommodation for young people.

The report was published after the death of 16-year-old William Lindsay, who took his own life in Polmont Young Offenders Institution two days after being sent there on remand.

Approximately half of the 84 places in secure care in Scotland are occupied by young people from outside the country, the Kilbrandon Again report said.

It was also critical of the length of time those who committed childhood offences can have to disclose them for, with enhanced provisions meaning this can be the case until the person is 40.

Richard Holloway, the former bishop of Edinburgh, chaired the study of youth justice systems more than 50 years on from the 1964 Kilbrandon report, which led to the establishment of the current Children's Hearing System. He stressed an overhaul is "long overdue".

While the Scottish Government is bringing in legislation to raise the age of criminal responsibility from eight - the lowest in Europe - to 12, Mr Holloway called on ministers to "be more radical".

He said: "The age of criminal responsibility in Scotland has been a matter of concern for a considerable period of time.

"We have a system envied around the world through taking a progressive, welfare-based approach towards children at risk or in trouble with a strong focus on prevention and early intervention.

"However, the criminalising of eight to 11-year-olds has always been inconsistent with this approach.

"While we welcome the proposal to raise the age of criminal responsibility to 12, we do believe we can be more radical and increase the age of criminal responsibility in Scotland to 16."

The report was critical of the current system on sending 16 and 17-year-olds to adult courts, as it urged the set-up of a new youth system.

In addition it called for the Children's Hearing System (CHS) to record the circumstances of youngsters who are referred for help, whether they attend the hearings and whether their views are heard.

It said members of children's panels should reflect more closely the make-up of the communities that most of the children and families they deal with come from.

Mr Adamson said: "This report rightly recognises the devastating impact of poverty and inequality on every aspect of children's lives, including their attainment, mental and physical health and risk of being drawn into conflict with the law.

"It is clear that that treating vulnerable children as criminals stigmatises them and can have a life-long impact, including on education and future employment."

Paul Carberry, director of Action for Children in Scotland, said despite a fall in the number of children appearing before the courts and children's hearings, there was a concern "young people with the highest and most complex needs seemed to be most vulnerable to being involved in the adult criminal justice system".

He added: "We turned to Richard Holloway and his fellow panellists, Kaliani Lyle and Ruth Wishart, to ask them once again to bring their independent minds to bear on how well Scotland supports children and young people in trouble.

"Once more, the panel have come up with a piece of work that gets to the heart of the matter.

"Fifty years on from the Social Work Scotland Act, the message is that we haven't got there yet and our systems require an urgent review."

A Scottish Government spokeswoman said: "Raising the age of criminal responsibility to 12 is the right reform for Scotland at this time, and will mean that we are leading the way in the UK, ensuring no child under 12 will be treated as a criminal or accrue a criminal record.

"We know there is more to do to improve outcomes for children and young people who need care and support. And it is right that we keep all parts of that system under review, including children's hearings.

"We will consider this report's findings alongside the wider, independent care review that is under way."