The chief constable of Thames Valley Police, Jason Hogg, has been suspended with immediate effect.
The police and crime commissioner says it's to allow for an investigation by the watchdog into claims of gross misconduct.
Matthew Barber says it relates to an alleged lack of honesty and integrity - and confirms there's no criminal investigation.
“As Police & Crime Commissioner it remains my duty to secure the maintenance of an effective and efficient police force. It therefore falls to me to appoint a Temporary Chief Constable. I intend to make such an appointment by the end of the month, until which point the Deputy Chief Constable, Ben Snuggs, will fulfil those duties.
“This announcement will come as a shock to many across Thames Valley, especially to our hard-working police officers and staff, but it is right that any allegations of this serious nature are dealt with consistently and investigated properly and thoroughly. I urge the IOPC to conclude their investigations and to present evidence as swiftly as possible.
“It is for the IOPC to lead on any communication about the investigation itself, but in the meantime, I will continue to hold Thames Valley Police accountable for their performance and work closely with the Force to ensure the police continue to protect the public, prevent crime and catch criminals.”