Clean Sheet, an ex-offenders charity, is speaking as a new report shows that some children are being held in youth prisons up to 187 miles from their homes.
Jane Gould told Premier: "Up to 32 per cent of our current young offenders institution population are children who've been in care - so there is no family unit there to make them feel the sort of things that we all expect and enjoy from our own family unit."
"The absence of this comfort and familiarity can lead to other forms of comfort being sought - i.e. acceptance by gangs."
Analysis by HM Inspectorate of Prisons found that each 25-mile interval that a child was held from home was associated with one less visit from a relative or friend.
The watchdog's report said: "Those children held furthest from home (over 100 miles) frequently said that their parents either no longer visited, or visited monthly or less."
Over the last decade the number of children in young offender institutions or secure training centres in England and Wales has fallen, dropping by more than two-thirds from 2,467 in April 2005 to 802 in April 2016.
There has also been a reduction in the number of places where children can be detained.
Jane Gould also told Premier it's important to pray for young people locked up so that they do not become isolated: "God has called us to set prisoners free.
"Part of that is to pray a very simple prayer that God... will visit them and touch them in their loneliness."
Listen to Premier's Hannah Tooley speak to Jane Gould here:
