MAN ON SIAN MURDER CHARGE.
Christopher Halliwell, 47, was arrested by Wiltshire Police on Thursday and charged on Saturday night with killing the 22-year-old from Swindon.
Miss O'Callaghan disappeared from the town's Suju nightclub a week last Saturday. She was last seen alive in CCTV footage filmed close to the nightspot in the early hours after a night out with girl friends.
She lived in a flat just half a mile away with her boyfriend Kevin Reape, 25.
Her body was recovered from an area 15 miles east of Swindon. Hundreds of people turned out to help a public search of Savernake Forest, near Marlborough, Wiltshire, after her mobile phone was traced to the area after she left the club.
But her body was discovered 15 miles away, close to the Uffington White Horse in Oxfordshire on Thursday last week.
Halliwell was arrested on Thursday at a taxi rank at an Asda supermarket in Swindon.
On Saturday night as many as 10,000 attended a lantern vigil at Swindon's Polo Ground, where Chinese lanterns and balloons with messages of condolence were sent flying into the night sky. Hundreds of floral tributes were left outside Suju before being cleared away on Saturday as the nightclub reopened for the first time since Miss O'Callaghan's disappearance.
Meanwhile police officers and forensic experts were continuing to search a field in Gloucestershire where they found remains believed to be those of a woman killed between 2003 and 2005.
PROBE: The scene in Gloucestershire where remains thought to be of another woman have been found TRIBUTE: People release Chinese lanterns in Swindon, below, in memory of Sian O'Callaghan., right