Rashan Charles, the 20-year-old who died while being restrained by police in east London, had swallowed a paracetamol and caffeine tablet before his arrest, it has been confirmed.

Charles, whose death triggered protests and demonstrations across London, died after being followed into a shop in Dalston by officers who surveyed him getting out of a car. He was tackled to the ground with the help of a member of the public.

Police said they had spotted Charles "trying to swallow an object" before entering the shop and being taken ill. He was taken to the Royal London Hospital, but died a short while later.

The Independent's Police Complaint's Committee (IPCC) launched an investigation into the incident including forensic analysis of "an object that was removed from Rashan's airway by paramedics".

In an update to the investigation, the IPCC said the substance which Chalres swallowed was a mixture of caffeine and paracetamol wrapped in plastic.

Cindy Butts, IPCC Commissioner overseeing the investigation, said: "Since the tragic death of Rashan Charles in the early hours of 22 July there has been much public speculation and anger.

"The IPCC is independently scrutinising all the evidence, in order to provide answers for Rashan's family, friends and the wider public – but we don't work in a bubble. We are well aware of the discussion that's going on around the case and the need to do our part to help people have confidence in our investigation.

"We received analysis of the contents of a package that paramedics removed from Rashan's airway after he was detained and restrained by a police officer and member of the public. Following a very constructive meeting with Rashan's family, we stated that the package did not contain controlled substances. We did not provide further details, because the contents of the package are not directly relevant to our investigation – we are looking into the circumstances of Rashan's death, not investigating Rashan.

"However, given the inflammatory nature of some ongoing speculation I will confirm that the package consisted of a mixture of paracetamol and caffeine wrapped in plastic. At this stage we have not been provided with a confirmed cause of death for Rashan and our investigation is ongoing.

"Rashan's family have appealed for calm, while we undertake our important work. I would echo their appeal and reassure the public that our investigation will consider every shred of available evidence."

Rashan Charles
Rashan Charles died after he was chased and restrained by police in a shop on Kingsland Road, east London Facebook/LorraineKing