The incidents have all involved elderly women and occurred in the late evening of Tuesday, 3 January through to the morning of Wednesday, 4 January.
The man is reported to have first exposed himself to a woman through her letterbox in North Dagenham, on Tuesday 3, January at around 10:15pm.
He then exposed himself in the same way to another elderly woman on Mayesbrook Road in Dagenham at about 11:05pm.
It is believed he committed other offences that night of the same nature, also in the Dagenham area.
He is also believed to have been looking through windows, knocking on doors, and acting suspiciously on Lilliechurch Road in Dagenham.
The man wore dark clothing and a black crash helmet during all the incidents and was riding a dark colored motorbike or moped.
Detective Constable Sky Mulvey from the East Area Command Unit said: “These incidents were very distressing for the victims and we are determined to swiftly bring the person responsible to justice.
“We are extremely keen to get any information, CCTV or door cam/doorbell footage in connection with the incidents. If you know who this man is, please contact us, or Crimestoppers anonymously, as a matter of urgency.”
Any witnesses or anyone with any information is asked to call police on 101 or contact via Twitter @MetCC. Please quote reference CAD 4471/04JAN.
To give information anonymously, contact the independent charity Crimestoppers on 0800 555 111.
Featured image: Met Police