A police chief has been suspended while claims of inappropriate behaviour towards female officers and staff are investigated.
A number of serious allegations against A von and Somerset Police chief constable Nick Gargan have been made, police and crime commissioner (PCC) Sue Mountstevens said.
Ms Mountstevens added that she had decided to suspend M r Gargan, whom she appointed as chief constable in March last year, to "protect the integrity of the investigation".
She said: "Following a number of serious allegations of inappropriate behaviour towards female officers and staff by the chief constable, Nick Gargan, I have decided to refer the matter to the Independent Police Complaints Commission (IPCC), who will now conduct an independent investigation.
"Due to the public interest in the case and to protect the integrity of the investigation, I have decided to suspend the chief constable while the independent investigation is carried out."
The IPCC confirmed it has launched an independent investigation.
Avon and Somerset deputy chief constable John Long will act as temporary chief constable and all officers and staff have been informed of this decision.
Ms Mountstevens added: "I would like to assure the communities of Avon and Somerset that the constabulary remains a high-performing force. Both police officers and staff are committed to ensuring the area remains a safe place to live, work and visit."
Mr Gargan started his career with Leicestershire Constabulary in 1988 after completing a degree in French and politics at the University of Leicester.
He worked extensively on the investigation into the death of Diana, Princess of Wales, eventually giving evidence at the inquest into her death and the death of Dodi Fayed.
The chief constable was awarded the Queen's Police Medal in the New Year's Honours List 2012.
A spokesman for Avon and Somerset Police said: "The matter has been referred to the IPCC by the Police and Crime Commissioner. It is not appropriate for us to comment any further."