"People need to be held to account for my son's death. There needs to be a full inquest, in front of a jury of ordinary men and women, to find out the truth."
The police watchdog the Independent Police Complaints Commission (IPCC) is compiling a report that will be passed to a coroner in the autumn.
An inquest into the death of the father of four will take place in January but there is a possibility that some evidence about police operations will need to be heard in secret, which would mean that a special type of public inquiry would need to be held instead.
Mr Duggan died when officers blocked the grey people carrier in Tottenham, north London, on August 4 last year as part of a pre-planned operation, and shot him in the chest.
A non-police issue handgun, converted from a blank-firing pistol to one that shoots live rounds, was recovered close to the scene but initial reports that Mr Duggan fired at officers were dismissed after ballistic tests found that a bullet which lodged itself in one officer's radio was police issue.