A man in his 30s has died while in custody at a police station in Swindon, Wiltshire police said. He had been in custody at Gablecross police station since Saturday morning, and became unwell on Sunday morning. He was declared dead at about 9am on Sunday, the force added. The incident has been referred to the Independent Office for Police Conduct (IOPC). A spokesperson for the IOPC said the watchdog has begun an investigation into the incident. “We have begun an independent investigation into the circumstances surrounding the death of a man in custody at Gablecross police station in Swindon this morning,” an IOPC spokesperson said. “We understand that the man had been held in custody over the weekend and became unwell this morning [19 June]. “An ambulance arrived soon after but sadly he was pronounced dead at 9am. We were notified by Wiltshire police shortly after and declared an independent investigation. IOPC investigators have today attended the police post-incident procedures to begin gathering evidence.”