The police watchdog is investigating five officers for potential misconduct after a probe was launched following the death of a man in east London.
Edir Frederico Da Costa, 25, died six days after he was detained when a car was stopped in Newham, east London, in June, as part of a series of routine stop and searches on vehicles in the Beckton district of the borough.
In an update issued on Tuesday, the Independent Police Complaints Commission (IPCC) said investigators are set to formally notify five Metropolitan Police officers that "the level of care they provided Mr Da Costa during restraint and after he became unwell may have constituted misconduct".
The IPCC said it is "now investigating this potential misconduct" and added that the serving of misconduct notices on officers does not indicate guilt, or mean that misconduct proceedings will necessarily follow, reports ITV News.
At a post-mortem examination carried out on 22 June, a number of packages were removed from Mr Da Costa's throat.
The pathologist has not yet determined the cause of death. The preliminary examination found there was no fracture of the neck or spinal injury, no broken collarbone and no signs of bleeding on the brain.
Mr Da Costa's death sparked protests in east London.
The IPCC said since the opening of its investigation, witness statements from police officers, medical staff and members of the public have been collected, as has body-worn video footage of the first aid administered to Mr Da Costa.
IPCC Associate Commissioner Tom Milsom said: "We are very aware of the community concerns following the death of Mr Da Costa.
"So as well as providing regular updates to the family and communicating with the officers involved, we will, when appropriate, also inform the wider community about the progress of our independent investigation."