Detectives investigating a series of linked sexual assaults in the Hackney Marshes area have released an E-FIT image of a suspect they wish to identify.
In each incident the description of the suspect and his actions have been very similar.
Lone women have been out either walking or jogging when they have been approached by a male on a bicycle who has grabbed their buttocks from behind, or touched their genitals, before making inappropriate comments and riding off.
The suspect is described as a light skinned man, possibly mixed race, aged 16/17, who is usually wearing a grey tracksuit.
Detectives received 22 reports between February and June, but believe there could be more incidents.
Det Con Hannah Rodericks, from the Central East command unit, said: "I understand this news may cause considerable concern among the community.
"We in the Central East command unit share that concern and are doing everything we can to identify and bring to justice the person responsible."
Anyone with information is asked to call 101 - quoting ref 4216097/22 - or tweet @MetCC.
To remain 100pc anonymous, visit the Crimestoppers website or call 0800 555 111.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here