A former police and crime commissioner is being investigated for possible criminal conduct in relation to his use of social media.
Jason Ablewhite resigned as PCC for Cambridgeshire and Peterborough on Monday after three years in the job.
The Independent Office for Police Conduct (IOPC) said a member of the public made a complaint to police.
An IOPC spokesman said Mr Ablewhite "exchanged a series of messages with the adult... through social media".
He added: "Our investigation is in its early stages and we are in the process of gathering information."
The IOPC can only investigate a PCC if there is an indication that a criminal offence may have been committed.
An acting commissioner will be appointed and serve until the next scheduled election for the post in May 2020, a spokeswoman for the Cambridgeshire Police and Crime Panel, said.