More than 40 people contacted police after an appeal was broadcast on Crimewatch about a man who raped two women in Manchester.
Both 21-year-old women were attacked in Fallowfield - the first in May 2007 and the second in May last year.
Greater Manchester Police is linking the attacks, in which the women were targeted as they walked home alone in the early hours.
The force said the calls would now be looked at as part of police inquiries.
Pushed into alley
Crimewatch, which was broadcast on BBC One on Tuesday, showed reconstructions of both rapes, the first of which happened at about 0200 BST, when the victim was walking along Whitby Road.
Police said the attacker pushed her into an alley and throttled her until she was unconscious, before raping her.
In the second attack, the woman was walking home from work along Egerton Road at about 0310 BST when she was grabbed from behind and dragged down an alley near the junction with Mauldeth Road.
Police said that after the rape the attacker told the woman to stay in the alley until he had left.
In both cases the attacker is described as Asian, 6ft (1.82m) tall, aged in his early 20s, of slim build and was wearing dark clothing.
Anyone with information is urged to contact police.