A 15-year-old boy, who was helping officers with their investigation, has been confirmed as the person spotted wearing the sinister horror mask - apparently inspired by the film V for Vendetta - on several occasions.
CCTV cameras captured him walking through the city on the evening of Wednesday last week and numerous people reported seeing him last Thursday and on Saturday.
But detectives are still no closer to finding the man responsible for pouncing on a 19-year-old Canterbury Christ Church student in the Longport area on Friday.
They say there are no independent witnesses to the attack and want anyone with information to come forward.
The suspect is described as white, 5ft 11in tall, skinny and wearing a black hooded top, dark jeans and a white V for Vendetta mask - similar to the one seen in the CCTV images.
There have been many other sightings of people in the city wearing masks, but no other attacks have been reported.
A CCTV image of a masked man approaching students in Canterbury
Ch Insp Mark Arnold, from Kent Police, said most reports of people wearing masks can be explained as part of the run up to Halloween and Bonfire night.
He added: "A number of local shops in Canterbury have been selling the V for Vendetta masks in the past several weeks and dozens have been sold.
"Whilst it's not unusual for people to be wearing fancy dress, including masks, I would warn everyone to celebrate responsibly and not do anything which may cause alarm, distress or fear to others.
"I would also urge all students to follow the safety advice particularly to stick to well-lit areas, avoid short cuts and avoid travelling alone at night and report any suspicious incidents where someone makes an approach or tries to touch you."
Reports of V for Vendetta mask sightings in Canterbury
The 15-year-old boy was questioned by officers earlier this week after being taken to a police station by his father.
Meanwhile, a 22 year-old man arrested on Monday night over the sightings has been interviewed and bailed until November 11 pending further inquiries.
Police have stepped up their patrols of Canterbury and issued safety advice after the spate of sightings.
The security team at Christ Church University also increased patrols as the search for menace continues.
Safety advice issued by the university included sticking to well-lit and busy areas, particularly at night - and avoiding shortcuts through isolated areas.
It also urged students to avoid travelling alone at night, plan their route before leaving as well as to look and act confidently.
Witnesses or anyone with information is urged to phone police on 101 or the investigating team on 01227 868278.