Last sighting of pregnant Anneli: Police release CCTV footage of Suffolk victim

Detectives are investigating whether the murderer could have been recently released from prison

Police yesterday released CCTV footage of the last moments of a murdered prostitute as detectives investigated the possibility that the killer may have recently been released from prison.

The images of Anneli Alderton, which have been released by Suffolk Police, show her on the 5.53pm train from Harwich to Colchester on 3 December. This was the last official sighting of Anneli, who was three months pregnant. Her body was found in woodland a week ago.

Detective Chief Superintendent Stewart Gull, who is leading the investigation into the killing of five women in Ipswich, yesterday appealed to the public: "We now need to piece together Anneli's movements after this image was captured. At what station did Anneli get off the train? And where did she go after that?"

Suffolk detectives were last night trawling through records of all high- and low-risk offenders currently monitored by special teams who manage serious violent and sexual offenders. There are nearly 400 registered sex offenders in Suffolk. Around half of these have committed offences against women and more than 20 are considered high risk.

A senior police officer was a client of the murdered women, according to a report in the News of the World. The officer, who works for a neighbouring force, was a regular client of Paula Clennell and one of the other victims. Ms Clennell made the disclosure to police when asked for information about clients before her disappearance.

Detectives investigating the murders refused to confirm or deny the report.

Police are considering whether the killer could have been released from a jail outside the area. Harry Fletcher, from the National Association of Probation Officers, said probation staff have been quizzed. "This could be someone recently released who has been locked up for a while. Anyone who has committed offences against women will be looked at."

Experts from the FBI's Behavioral Science Unit in Quantico, Virginia, in the United States, are also understood to have been consulted. They are credited with revolutionising crime investigation, especially into serial killings. It is also understood that investigators have questioned staff at a local prison whose inmates include men who have committed serious domestic violence offences.

The police hotline - 0800 096 1011 - has received more than 9,000 calls. Suffolk Police are being helped by 350 officers and staff from 31 other forces, including number-plate recognition vehicles from Merseyside.

The images of Anneli Alderton show her wearing a black jacket with a fur-lined hood, a grey top, blue jeans and white shoes. She was carrying a shiny nylon shoulder bag, tied with a cord. She was the second woman to go missing. All were prostitutes, all drug users, and all have been found dead and naked in remote places, with no sign of a struggle or serious sexual assault.

The largest murder hunt in Suffolk history stepped up a gear after the discovery of two bodies near the Old Felixstowe Road on Tuesday.

Five separate inquiry rooms have been set up, each handling a separate murder. Yesterday there were reports that police had a list of five suspects, but Mr Gull said: "I'm not going to be drawn on the number of people we are interested in. Nobody has been spoken to as a suspect at this time." He was careful not to use the phrase "serial killer", he said. "It's possible we're looking for the same killer, but there may be more than one involved."

Not all the people spoken to are local, he said, and not all were clients of the women. Mr Gull said that no foreign police force had been contacted. Officers have spoken to the driver of a blue BMW they were trying to trace earlier, but "may need to speak to him again".

Police are investigating whether the women may have been drugged by the killer, or had their drug supply spiked by a dealer. All five were believed to have been on heroin. Toxicology reports may take more than a month to come through.

The fear is that the killer may strike again before Christmas, possibly in Norwich, Peterborough, Nottingham or another town with a prostitute community that has links to Ipswich.

There have been no arrests, no vehicles seized, no search warrants issued and nobody spoken to under caution. Nevertheless, Mr Gull insisted: "We are making good progress."

His boss, Chief Constable Alastair McWhirter, likened it to a jigsaw puzzle. "We've got the edges of it all set out and we just need to fill in the middle."

One inquest has already been opened and the others are expected to open on Monday. Police are hoping for DNA leads as a result of the post-mortems.

Senior police officers have said there is concern the case could turn into "another Soham". They fear the killer could turn out to have been known to the police but not placed on the sex offenders register.

One said: "The nightmare scenario will be that this turns out to be another Huntley, someone who was known to police but slipped through the net. There is enormous pressure on the investigators and that is why they have been quick to involve other forces from the outset."

The first body to be found was that of Gemma Adams, 25, a fortnight ago. The women are likely to have gone with the killer willingly, said Mr Gull. "These are working girls. They are going to get into cars voluntarily because that is the nature of their business."

At least 1,000 personal attack alarms have been sold to women in Ipswich. Mr Gull has urged local women to take "sensible precautions" but not to panic. "These were all working girls. There is nothing to suggest that other women or members of the community are at risk."

On Friday, the parents of victim Tania Nicol said their daughter was "a caring, loving, sensitive girl who would never hurt anyone. Unfortunately drugs took her away into her own secret world - a world neither of us were aware of."

Addressing other bereaved families, her father Jim Duell said: "They can't take away our memories. They can't take away our love, our fortitude, our courage." Of the girls, Mr Duell added: "We have our memories of the good times, and a thankfulness that they are now at peace."

Ms Nicol, 19, was the first to go missing. She was last seen outside Sainsbury's in the London Road, close to the red light district, on 30 October. She was wearing a light top, blue cut-off jeans and pink, sparkly high heels. Two weeks later, on 14 November, Gemma Adams went missing. The last sighting was in Victoria Street. She was wearing jeans, a black waterproof, and white trainers with chrome trim.

Ms Adams's body was the first to be found, two weeks ago at Belstead Brook near Hintlesham in the countryside just outside Ipswich. Six days later Ms Nicol was found in the same brook, this time at Copdock Mill. Both women were naked.

Anneli Alderton, 24, from Colchester was found in woodland near Naction a week ago.

On Tuesday the bodies of Annette Nicholls, 29, and Paula Clennell, 24, both from Ipswich, were found. Ms Nicholls had gone missing from the town centre on 4 December, and Ms Clennell was last seen at night on the London Road five days later. Ms Alderton had been asphyxiated. Ms Clennell died due to "compression of the neck". The cause of death in the other cases is still unclear.

CCTV: Last sighting caught on film

Anneli Alderton stands in an empty railway carriage on the 5.53pm train from Harwich to Colchester. The date is 3 December and police now believe that this grainy CCTV footage represents one of the last confirmed sightings of Ms Alderton before she disappeared.

Officers are now searching through hours of CCTV recordings in an attempt to establish where she left the train, and detectives haverenewed an appeal for information.