A 17-year-old girl is believed to have been sexually assaulted on three separate occasions as she walked home from a night out.
Police said her ordeal started shortly before midnight on Friday 29 September when she was picked up on camera being carried by a man in Cambridge Heath Road.
The pair are then seen appearing to go into a doorway in the same road, after which the man, who was wearing dark clothing, is not seen again on camera.
Items of the top half of the girl’s clothing were subsequently found nearby.
Shortly after midnight, another CCTV camera picks up the girl stumbling down Mint Street, being followed by a different, bearded male, on a racing bicycle.
Officers said the man followed the teenager along Mint Street, into Three Colts Lane, and then as she heads in the direction of Bethnal Green Overground station.
When the next camera picks her up, the man has approached her and they have reached Corfield Street.
Some time later, the camera picks up the man leaving the area and walking away.
The girl, whose clothing appears dishevelled, emerges shortly afterwards and goes further down Corfield Street.
Just minutes later, at around 12.45am, detectives believe the victim suffered a third attack, possibly involving two or three men.
The CCTV captures a third, different man walking down Corfield Street and joining two other figures under some trees. He appears to bend down towards a spot on the curb in between some parked cars.
Detectives believe it was at this point that the victim was sexually assaulted.
A short time later, a member of the public spotted the teenager lying on the ground in Corfield Street in a state of distress and called 999.
Detectives believe it is possible that she was drugged and are in the process of carrying out toxicology tests.
Detective Inspector Suzanne Jordan, from the Metropolitan Police’s child abuse and sexual offences command, said: “This is a horrific multiple sexual assault on an young female who was simply making her way home after a night out.
“We would like to thank the members of the public who intervened to help her and possibly prevented her ordeal from continuing even further.
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“We believe two of the three were very serious sexual assaults indeed, and are determined to catch the persons responsible for these hideous crimes.”
Police have released images of two men wanted in connection with the assaults.
Anyone with information should call police on 101 or via twitter at MetCC, or contact Crimestoppers on 0800 555 111 or online at http://www.crimestoppers-uk.org.