Detective Superintendent Steve Fulcher said: “I would like to thank the local community and the media for all their help and support in this case. This is understandably a deeply distressing time for Sian’s family and I would like to express my gratitude to the media for leaving them to grieve in peace.”

Key points

• Soon after Sian was reported missing by her boyfriend, Kevin, officers became very concerned for her safety and welfare as this behaviour was completely out of character.
• As a result of CCTV and technical analysis of her mobile phone we established Sian left Suju nightclub in Swindon at 2:52am intending to go home. Her mobile phone was live and our technical means indicated that at least the phone and possibly Sian were within a 6 1/2 kilometre radius of a mobile phone mast in Savernake Forest.
• Through CCTV and other images officers were able to establish that a green Toyota Avensis had been seen near to Suju nightclub during the relevant time. From this we were able to identify the registration of the vehicle which led us to believe that Sian had been abducted and taken away in this vehicle. The investigation proceeded on the basis that Sian was still alive with the aim of finding her.
• Separate searches commenced in the Savernake area and to locate the vehicle and individual driving it.
• Late yesterday morning (Thursday) the vehicle was stopped and a man was arrested on suspicion of kidnap. He remains in custody at Gablecross Police Station.
• This man indicated two locations. One near Uffington in Oxfordshire where a body of a woman, believed to be Sian, was discovered. The body has since been recovered.
• A post-mortem examination is currently taking place.
• The second location is Eastleach, Gloucestershire, where we believe a second body may be. Searches are currently being conducted in this area which could take several days.
• Subsequently the man in custody was arrested on suspicion of kidnap and two murders. At this time, he has not been charged and remains in custody. An application to magistrates for a warrant of further detention may be made later today.
• With regard to the second body, we are concentrating our efforts on a historic case of one missing adult from Wiltshire.
• If you have any information you believe is directly relevant to the Sian O'Callaghan inquiry, please contact Wiltshire Police on 0845 408 7000. You can also contact CrimeStoppers on 0800 555 111 where details may be left anonymously if preferred.
• If you are concerned about someone who is missing, the charity Missing People offers a specialist support service for families and relatives of missing people and for the 250,000 people who go missing each year in the UK.
• More information is available at the Missing People website www.missingpeople.org.uk/help
• The charity also operates a 24 hour confidential Freephone helpline on 0500 700 700.

Chief Superintendent Steve Hedley said:

• Cases such as this are very rare in Swindon and Wiltshire as a whole.
• We are very grateful for the support of the public and hope that the positive relationship between the local community and police continues.
• Despite the rarity of cases such as this, it is important for the public to adhere to personal safety advice when out late at night.

Some basic measures you can take to reduce your chances of becoming a victim of crime include:

• Always make sure someone knows where you are going and what time you will be home.
• Stick with friends when you are out and about.
• Try not to walk alone.
• When walking with friends, stick to well lit, busy areas and never be tempted to take short cuts through quiet or unlit areas.