The Department of Home Affairs says the prison has almost 15 per cent more inmates than it was designed for.
A Freedom of Information request asked how many prisoners the Jurby facility was designed to hold, and how many people were currently incarcerated there.
In its response, the department said the official capacity was 141 - and on April 7 there were 159 inmates.
It added there were 26 cabins on top of the permanent accommodation, all of which were being used.
Government reveals TT viewing figures
Just one in five people who sign up for the Department for Enterprise's TT streaming service pay for the live coverage.
Final wind farm hearings set for July
The final meetings and hearings for the proposed Mooir Vannin Offshore Wind Farm have been announced.
Cocaine dealer to appeal 14-year jail term
A Douglas man serving a 14 years in jail for his part in a cocaine-smuggling operation is to appeal against his sentence.
Infrastructure Minister defends road checks for cat’s eyes work
Roads are always inspected by the Department of Infrastructure before workers install cats eyes.
Beauty brand Charlotte Tilbury launches at Boots this weekend
The wait is finally over - Charlotte Tilbury is launching at Boots this Friday.
Isle of Man Energy confirms no gas price rise
Isle of Man Energy says gas prices will stay the same for customers despite rising wholesale costs.
Countdown on for World Downhill Skateboarding Championships
A huge skateboarding event has released a video looking forward to this week's action on the Isle of Man.
Laxey's La Mona Lisa changes hands after 22 years
The owners of a long-running Italian restaurant are handing over the reins.
