Detectives believe a series of sex attacks which target lone women at night are linked.
Eight women have been assaulted in Clapham, south London, in the last month, forcing police to raise patrols.
All of the women described the man as being of Mediterranean or middle-eastern appearance with dark hair, police said.
Detectives said the man is targeting lone women late at night, with all eight victims in their 20s and 30s.
The latest attack was on Wednesday night when a woman was pushed into a block of flats along Sudbourne Road and sexually assaulted.
Earlier that night a 28-year-old woman was grabbed by a man on Southwell Road before he ran off after she screamed.
Police are urging woman to be vigilant following the spate of attacks.
Superintendent Rob Applegarth, of Lambeth borough, said: "We are aware of eight assaults which we are linking at this early stage. We have increased police patrols in Clapham and Brixton Hill and urge women to think of their personal safety.
"We are also releasing CCTV and an image of a man we would now like to speak to in connection with these incidents."
The first attack took place at 11.30pm on October 9 when a woman was grabbed and sexually assaulted on Clitheroe Road.
A second incident took place in the early hours of Saturday October 10, and on October 22 a man placed his hands up the dress of a woman at around 9pm on Trent Road.
And earlier this week, on Monday night, three assaults took place in the space of three hours all in close distance with each other.
One 35-year-old woman was grabbed from behind at around 7.05pm, and just over an hour later another woman was also assaulted from behind as she entered her home.
CCTV footage of the attack, which took place on Roseberry Road at 8.15pm has been released by police.
Again on the same night, at 9.36pm, a man exposed himself to a 28-year-old woman on Sandmere Road who alerted police.
Police are urging anyone who recognises the man in the CCTV footage to contact them.
Detective Sergeant Gordon Barclay, who is leading the investigation, said: "Lambeth police would like to advise women to remain vigilant when travelling at night and would also ask that anybody who may have any information regarding these offences to make contact with police.
"The CCTV and the still are of good quality and we are confident that someone will be able to identify this particular man. I urge anyone with any information about these incidents to call us urgently."
A man was arrested by police in connection with one of the assaults but was released on Wednesday and bailed until November.