One of the girls, who is 14, was yesterday in intensive care at the Queen Alexandra Hospital, Cosham, Hampshire.
Detectives said they wanted to talk to Peter Tobin, who has disappeared from his home at Leigh Park, Havant, Hampshire.
Detective Chief Inspector Nick Imber said: 'We are also very concerned for Mr Tobin's own safety, particularly since he deposited many of his valuables with his wife before disappearing.'
Police were first alerted on Wednesday night when the 14-year-old and her 15-year-old friend, who live in the Havant area, were reported missing.
On Thursday morning the 15-year- old returned home and said that she and her friend had been held prisoner and sexually assaulted. Police went to an address where they found the 14- year-old, who was taken to hospital.
Mr Tobin, a Scotsman, who is 5ft 6ins tall, is reported to be driving a blue Austin Metro, registration number OMW 574Y.Reuse content