Two police officers have been suspended following allegations of a criminal offence and misconduct.
Gwent Police confirmed an independent investigation into the matter is being carried out by another force.
On Wednesday, Avon and Somerset Police said they are conducting an investigation into an allegation of a criminal offence involving a serving police officer.
One officer has been suspended while that investigation is carried out.
A second officer has been suspended amid allegations of misconduct.
The investigations are being managed by the Independent Office for Police Conduct.
Neither police force has provided details of where or when the alleged incident or incidents took place.
The South Wales Argus have reported that the investigations are related to an incident at a retirement party for former Gwent Chief Constable Julian Williams. Chief Constable Williams retired at the end of June.
Temporary Assistant Chief Constable of Gwent Police, Rhiannon Kirk, said: "Avon and Somerset Police are carrying out an independent investigation into an allegation of a criminal offence against a serving officer at Gwent Police, as well as an investigation into allegations of misconduct against other serving officers.
"As a result, two people have been suspended while enquiries continue. We’re unable to comment further at this stage."
A spokesman for Avon and Somerset Police said: "We’re carrying out an investigation into an allegation of a criminal offence made against a serving officer at Gwent Police. The officer has been suspended while this investigation is carried out.
"Alongside this, our Professional Standards Department are conducting an investigation into allegations of misconduct against other serving officers at Gwent Police. This investigation has resulted in a second officer being suspended.
"The investigations are being managed by the Independent Office for Police Conduct (IOPC). We’re unable to go into any further details at this stage."
