The police watchdog is to investigate the death of a 50-year-old man who was being held by Gloucestershire Constabulary.
The man died while in custody of police in the Forest of Dean last night, the Independent Police Complaints Commission (IPCC) said.
It has not yet named the victim and said a post-mortem and formal investigation is yet to take place.
The IPCC said that the man was held after police were called to an unspecified incident at the Stowfield Business Park at around 11pm.
He was believed to be driving a black Range Rover Sport prior to the incident.
Anyone with information is asked to email firstname.lastname@example.org or call 0800 096 9070.
The operation to police the badger cull pilot reached its full capacity at 8pm this evening, Gloucestershire Police said.
The force has said that the operation will be "operationally independent, impartial, even-handed and fair to everyone whatever their views, interest or involvement in the pilot scheme".
A document outlining the role of the police says it will mediate between parties if there are any protests as well as "responding to any breach of the peace".
A pensioner from Rotherham who is visiting the Cheltenham Festival remains missing on Wednesday.
Friends of 70 year old Philip Lucas last saw him around 5.50pm on Tuesday.
He was supposed to be staying in Cranham during the week of the festival.
Gloucestershire Constabulary have told ITV News West Country that they received a report of a possible sighting of Mr Lucas in the Kings Arms public house around 11.15pm on Tuesday, but there has been no confirmed information about his whereabouts.