The leads are running dry in a police investigation of a possible serial stalker in Wellington

The Weekend Herald revealed last July that police believed a spate of sex assaults in the capital might be connected to a sole offender, with as many as 12 incidents over seven years.

But re-testing DNA has resulted in no new leads, and they are no closer to an arrest than a year ago.

Detectives also say they're yet to find proof the attacks are linked to a single offender.