The Ministry of Justice is carrying out an investigation over misconduct allegations at HMP Nottingham.
The category B adult male prison in Perry Road is being investigated due to "misconduct allegations."
The MOJ is remaining tight-lipped about who is being investigated and would not tell Nottinghamshire Live the nature of the investigation.
A source claiming to be close to the prison said the investigation was around bullying but this has not been confirmed by the government department.
The Professional Trades Union for Prison, Correctional and Secure Psychiatric Worker (POA) said it was not aware of an investigation at HMP Nottingham.
The MOJ said an investigation into HMP Nottingham's governor Phil Novis has been carried out and concluded and he remains in post.
A spokesman for the department said: "An investigation is ongoing into misconduct allegations. It would not be appropriate to comment at this time."
