Mr Shaw, director of the Prison Reform Trust for 18 years, promised in an interview with The Independent to make sure that prisoners who attract the interest of lawyers and campaign groups do not exhaust his resources.
Mr Shaw, 46, who takes up his new post on 11 October, said: "It is one of the problems of the present prison ombudsman system that it is used very little by young offenders, remand or short-term prisoners. Yet we know the treatment of youngsters in some jails visited by the Chief Inspector of Prisons is lamentable."
He added: "What you must be careful of is not to superserve the lifers, the long-term prisoners, the more articulate inmates, the prisoners whose complaints appear attractive to lawyers."
An outspoken critic of prison conditions in the past, Mr Shaw becomes the second ombudsman to take up the post since it was created five years ago after the riots at Strangeways prison in Manchester.
"The prisoner with the lawyer and the support group is no more entitled - though also no less entitled - to the support and investigative powers of my office than a 16-year-old boy who is in for a month."
The ombudsman last year received more than 2,000 complaints from prisoners dissatisfied with the response of the prisons' internal complaints system. Of the 30 per cent investigated, 36 per cent were upheld. Mr Shaw is likely to face a significant increase in complaints once the Human Rights Act comes into force next year, as it will open to challenge many aspects of prison life.Reuse content