A nurse who went missing after being infected with malaria during a medical trial is being investigated over allegations of a sex attack.
Matthew Lloyd, 35, came forward in the Netherlands on Monday after he missed an appointment as part of the trial.
The nurse, who works at Southampton General Hospital, had been arrested and bailed over an attack on a woman, 20, on 22 August, the BBC has learned.
Mr Lloyd has not been charged and was allowed to leave the country.
The woman was targeted twice by the same attacker as she walked home along Howard Road in Southampton.
Hampshire police said: "A 35-year-old man from Southampton has been arrested on suspicion of sexual assault and bailed until 13 December, pending further inquiries."
The force said its policy was not to reveal the name of anyone arrested in connection with an inquiry.
Mr Lloyd was reported missing when he failed to attend an appointment in Oxford on 7 October, where he was due to receive drugs in connection with the trial.
Police said he could die if he did not receive urgent medication and issued an appeal for help in tracing him.
The nurse had phoned in ill to work in the days immediately before his appointment.
He was spotted on CCTV in Kings Cross, London, and police suspected he had travelled abroad after they discovered he had his passport and £900 in cash in his possession.
He contacted Dutch police on Monday and is being assessed in hospital.
Police have refused to reveal the exact location where he came forward and added that he did not have any known links to the country.