A police officer who Tasered the founder of a race relations group in the face is being investigated for gross misconduct.
Judah Adunbi, 63, was Tasered following a dispute when he was mistaken for a wanted man outside his Bristol home in January.
The Independent Police Complaints Commission said it was investigating the conduct of two officers involved.
Avon and Somerset Police said it was co-operating with the watchdog.
Mr Adunbi was approached by two officers who mistook him for a wanted man. He confirmed he was not the suspect they were looking for but refused to give his name.
After a dispute he was Tasered and arrested. Charges for a public order offence and assaulting a police officer were later dropped.
The force voluntarily referred the matter to the IPCC, which has now confirmed it has served the officers with "gross misconduct notices".
A spokesman said the notice "is not judgemental in any way".
Independent Police Complaints Commissioner Cindy Butts said: "The incident in which Mr Adunbi was Tasered has attracted significant community concern.
"As our investigation is ongoing the IPCC is limited in what can be released into the public domain, and we would ask for patience while our work is carried out."
Avon and Somerset Police said it "continued to co-operate" with the investigation but added it could not comment further.
It is the second time Mr Adunbi, who was a founding member of an independent group between the police and prominent members of the Afro-Caribbean community, has been mistaken for the same man.
In 2009 he won a wrongful arrest case against the force and was awarded compensation, although a Taser was not used in that incident.