The following is a joint statement issued by Wiltshire Police and the Crown Prosecution Service in Wiltshire.
At 9.20pm on Saturday 26th March 2011 Christopher John Halliwell, aged 47, of Ashbury Avenue, Swindon, was charged by Wiltshire Police with the murder of Sian Oâ€™Callaghan.
Simon Brenchley, District Crown Prosecutor, CPS Wiltshire said: â€œI have been working closely with Wiltshire Police and now have authorised them to charge Christopher Halliwell with Sian Oâ€™Callaghanâ€™s murder.
â€œHaving reviewed the evidence, I am satisfied that there is sufficient to charge him, and that it is in the public interest to do so.
"I must remind the media to take care in reporting events surrounding this case. Mr Halliwell has been charged with a serious offence and is entitled to a fair trial. It is extremely important that nothing should be reported which could prejudice any trial.
â€œI will keep liaising closely with the police as their investigation continues.â€
Mr Halliwell remains in police custody at Gablecross Police Station in Swindon. He is due to appear before Swindon Magistrates Court tomorrow morning, Monday 28th March 2011.