Prisoners say they are being punished for speaking Welsh in a Welsh jail – because the guards cannot understand them.
Lags at HMP Berwyn in Wrexham say warders threaten to take away their privileges if they don’t speak English – because they fear prisoners are plotting or insulting them.
Accusations of discrimination by Welsh lags also include being denied interpreters at disciplinary panels.
The claims were revealed in a report by inspectors from the Independent Monitoring Board.
It said: “Some complaints concerned prisoners speaking Welsh who could not be understood by officers.
“It was alleged these prisoners were challenged with a review of their incentives and earned privileges.”
The jail, which opened in 2017, is the UK’s largest with 2,100 inmates who are encouraged to “embrace Welsh language and culture”.
A previous report by chief prison inspector Peter Clarke raised worries about the lack of staff being able to speak Welsh at the jail, where around a quarter of lags are Welsh.
He said baffled guards were unable to monitor prisoners chatting on the phone in Welsh and there was a two-month backlog of untranslated calls.
For public safety, all calls by prisoners are recorded and monitored, except those to MPs or lawyers.
A Prison Service spokesperson denied Welsh inmates were being penalised for speaking Welsh, adding: “We are providing extra staff training and mentors to encourage Welsh speaking at