The so-called Thursday Night Rapist may have struck for the 15th time in West Sussex.
Fears are growing following the rape of a 31-year-old woman in Chichester who was knocked unconscious after being attacked from behind.
The rape took place on Thursday night in the Sherborne Road area.
Detectives have spent the last 18 months hunting a man believed to be responsible for a rape and 13 indecent assaults, many of which have taken place on a Thursday night.
The attacker has been described by his victims as smelling of diesel fuel or petrol.
Detectives said the victim of the latest attack had been able to tell them the man "smelt funny" although she had little other memory of what happened.
Detective Inspector Neil Fellingham, of the Operation Bobcat team, said: "We cannot at this stage definitely connect the offence with the others we have been investigating but we certainly cannot rule it out.
"I would advise women to take sensible precautions such as walking in well-lit areas and avoiding being alone."
The serial attacker is thought to have committed his first offence in 1995.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article