Police are investigating allegations that election leaflets featuring Cllr Rabina Khan have been tucked inside a Tower Hamlets Homes information documents that were given out.
Blogger Mark Baynes said he filmed a man, seemingly acting for the housing company, putting leaflets through the doors on the Green Bank estate in Wapping.
Three men, who allegedly lied to gain access, told security at Silver Wharf in Limehouse they were “working for Tower Hamlets in a normal political capacity” and should be allowed in.
Officers from the Met's Special Enquiry Team are investigating the allegations, in case election law has been breached.
Tower Hamlets Homes said the man was not a member of staff and it had not authorised the distribution of the leaflets.
A spokesman for the Met confirmed no arrests had been made and added: "This is very complex legislation, and we continue to work closely with the CPS. Any allegations made to police will be investigated.”
Ms Khan denies any wrongdoing.
A new mayor of Tower Hamlets will be voted in on June 11 after previous mayor Lutfur Rahman was stripped of the role and banned from standing for five years following a high-profile case at the High Court earlier this year.
The former mayor has endorsed Ms Khan whose election literature makes comprehensive reference to his administration's apparent achievements.