Police close to the investigation told The Times that they were looking at five other suspects and that they were no more than 50 per cent sure they had their man.

Tom Stephens, 37, was arrested at 7.20am yesterday, the day after a lengthy interview with him appeared in a Sunday newspaper. “Stephens is probably no more than midway on a scale of ten — about four or five,” a senior detective said.

Yesterday it emerged that Mr Stephens was first interviewed by police after only one woman had disappeared. Police have spoken to him three times since and his home and car had been searched. But no charges were brought against Mr Stephens, who knew all the victims and used to drive them to meet their drug dealers.

Between November 15 and December 10 the killer struck on four more occasions, accelerating the pace of his attacks after the bodies of the first two women were discovered.

Last night Mr Stephens’s father Douglas said: “I have heard what is being said on the news and all I am prepared to say is that Tom Stephens is my son.”

Mr Stephens worked at a Tesco store at Martlesham Heath, beside Suffolk Constabulary headquarters, and was a part-time taxi driver. His car was taken away for examination and search teams spent the day removing materials from his semidetached home in the village of Trimley St Martin, near Felixstowe.

A further search was being conducted at the house of his mother, Ellen Kite, in the village of Eye. Detectives can hold him for questioning until Friday morning.

Mr Stephens was born in Ipswich but grew up in Norwich, where he was a special constable with the Norfolk force in 1992-97. He married in February 1998 and lived in Ipswich with his wife Judith, a nurse. They separated in 2003 and about 18 months ago Mr Stephens began to use the services of prostitutes in the Ipswich red-light area.

In weekend interviews Mr Stephens said he knew all the dead women, that they trusted him and sometimes spent the night at his house. He said he had no alibis for the times of their disappearances and expected to be arrested before being released without charge.

According to reports last night, all five of the murdered women attended a house-warming party at Mr Stephens’ home two months ago. Police are trying to trace other men who were also there.

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