Detectives investigating the deaths of five women in Suffolk have been given permission to question a man for a further 24 hours.
The women were found naked between 2 and 12 December
Suffolk Police have until Friday morning to either charge or release Tom Stephens, of Trimley St Martin, near Felixstowe, who was arrested on Monday.
A second man, named locally as Stephen Wright, 48, remains in custody. He was arrested on Tuesday at home in Ipswich.
Both are being questioned over the murder of five prostitutes.
The naked bodies of prostitutes Gemma Adams, Anneli Alderton, Tania Nicol, Annette Nicholls and Paula Clennell were all found in the countryside within 10 miles of Ipswich and close to the A14, between 2 and 12 December.
On Wednesday morning the inquests into the deaths of four of the women opened and adjourned.
The hearing at Ipswich Coroner's Court found no clear cause of death for Tania Nicol and Annette Nicholls.
Anneli Alderton was asphyxiated and Paula Clennell died from compression of the neck, coroner Dr Peter Dean said.
The inquest into the death Gemma Adams, was opened last week.
Det Supt Andy Henwood told the inquest Miss Nicol had left her home in Ipswich on 30 October to go to work as a prostitute in the town centre.
She failed to return home and was reported missing, he said. Her naked body was found on 8 December in Belstead Brook at Copdock, near Ipswich.
The naked body of Miss Alderton was discovered beside a road in the village of Nacton, near Ipswich, by a member of the public on Sunday 10 December.
Miss Clennell was reported missing in the early hours of 10 December after she went to work in Ipswich's red light district.
Mr Henwood said that on 12 December the naked body of a woman was discovered on the Old Felixstowe Road and was later identified as Miss Clennell.
Annette Nicholls was reported missing on 11 December and was last seen by her mother on 4 December.
When officers attended the site of Miss Clennell's body at Levington, the Suffolk Police helicopter discovered the body of a second naked woman nearby.
The inquest heard the body was later identified as Miss Nicholls.
A post-mortem examination had been unable to establish the cause of her death.
Forensic teams have been searching an address in the London Road area of Ipswich where Mr Wright was arrested and carrying out searches at Mr Stephens' home, in Jubilee Close, and his mother's home in the market town of Eye, Suffolk.
Former special constable Mr Stephens, 37, was arrested at his home at Trimley St Martin.
Police have not confirmed or denied the identities of the people in custody.