The estranged husband of a woman whose disappearance five years ago led to a huge police investigation in Oxfordshire, has been arrested on suspicion of murder.

Jonathan Morton, a 65-year-old architect, was held after voluntarily attending a London police station on June 18 for questioning.

He was released the following day on police bail, without being charged, and will return on July 30, pending further inquiries.

Argentinian-born Gracia Morton, who was 41, went missing after dropping her four-year-old daughter off at her estranged husband's home in St Anne's Road, west London, on November 12, 1997.

She has not been seen since.

Officers have made extensive inquiries in London and Stonesfield, near Woodstock, where Mrs Morton, a former professional violinist, regularly went to stay at her husband's country cottage.

In September 2000, detectives spent two days searching woodland half a mile from Stonesfield after a tip-off and Metropolitan Police officers carried out forensic tests on a car recovered in Oxford last November.