THE cost of keeping lags locked up has hit £3.4billion a year — because they’re getting older.
Official figures show taxpayers fork out an average of £40,000 to detain a convict for 12 months, up £6,000 on the previous year.
The rise is partly down to the ageing jail population who need more care and medical treatment than younger prisoners.
Since 2010, the number of old age prisoners has tripled — there are now 1,500 in UK jails.
The cost of keeping the UK’s most dangerous inmates locked up inside the most secure jails now stands at about £85,000 a year each.
Another factor is the increase in longer sentences — with 48 per cent over four years in 2019 compared with 33 per cent in 2010.
Latest figures also reveal foreign prisoners cost £360million a year.
Reducing the number of foreign cons would have a major impact on overcrowding, one of the main reasons behind riots.
The Ministry of Justice said: “The rise in costs is due to increased investment in prisons and officers.”