The mother of Jordan Begley, who died after he was tasered by police in Manchester, said last week that she believes the officers thought they were dealing with someone else.
The Independent Police Complaints Commission is investigating whether Jordan was mistaken for another man with the same name from Sale, Greater Manchester, who was on the run.
Dot Begley said she pleaded with them not to use a taser gun on her son.
Jordan had recently undergone tests for heart problems.
He died in hospital two hours after being tasered.
Dot called police to their home following a row between Jordan and a neighbour.
The police claim they were told Jordan was carrying a knife. But Dot insists he did not have a weapon and she had not mentioned a knife.
“The response was so heavy-handed. Jordan was nine stone and they’d been called out to deal with a domestic argument,” she told The Mirror.
An independent post mortem found Jordan had carpet burns to his face, marks on his wrists and bruising to his limbs.