Detectives have released CCTV images showing one of the murdered Ipswich prostitutes on a train.
The picture showed Anneli Alderton on a train between Harwich and Colchester on December 3.
Police said they were taken from a camera on board the train and gave detectives a clear indication of what she was wearing on December 3.
Police believe the footage is one of the last sightings of Miss Alderton, whose body was found in woods at Nacton on December 10.
The images show her wearing a black jacket with a fur-lined hood, a grey top and blue jeans.
Police said they had received more than 8,000 calls following a public appeal for information - with about 1,000 people ringing a hotline in the past 24 hours.
They said officers from more than 30 forces - including Northern Ireland - were helping Suffolk Police in the inquiry.
Police say they are considering staging a reconstruction of the last known movements of one or some of the prostitutes.
The spokesman said no decision has yet been made on what any reconstruction would involve or when it would take place.
Meanwhile, Miss Alderton was three months pregnant, police have confirmed.
