Detectives searching for Sian O'Callaghan who went missing after leaving a nightclub in Swindon, said on Thursday they had arrested a man on suspicion of kidnapping her.

O'Callaghan, 22, has not been seen or heard of since leaving the Suju club in the early hours of Saturday, leading to a massive search by police and locals of the surrounding area.

Chief Superintendent Steve Hadley said the arrest was a significant development.

"A short time ago a man was arrested on suspicion of the kidnap of Sian O' Callaghan. He was arrested by Wiltshire officers in Swindon,"

"It is a significant stage in this difficult enquiry. Our priority is to find Sian and we are doing all that we can to do so."

He said O'Callaghan's family had been informed of the arrest. Her parents and boyfriend have made emotional pleas for her safe return.