Tobias Terpilowski–Gill, 26, fell from a balcony at his mother’s home in Kilburn, North London, on Sunday 21 December 2014.
The incident took place around 20 minutes after police had placed him in handcuffs, the IPCC said in a statement.
The photographer ran a business called Film and Stills and was widely exhibited throughout the UK, including at Camden Art Space in London, according to the business’s Facebook page.
Officers had been called to the property at 12.20pm on 21 December ‘due to concerns about his welfare’, added the IPCC statement, dated 22 January.
‘He was placed in handcuffs shortly after their arrival and arrangements were made to take him to hospital.’
Terpilowski–Gill was taken by air ambulance to St Mary’s Hospital, but died two days later from a head injury.
An inquest was opened at Barnet Coroner’s Court on 14 January.
The London Evening Standard reports that police officers are understood to have kept the photographer on a walkway at the flat while arranging to take him to hospital.
The IPCC statement continued: ‘IPCC investigators attended the scene on 21 December and an independent investigation was declared.
‘House-to-house enquiries and witness interviews have been conducted, CCTV footage of the incident has been seized and is being analysed.’
Anyone who may have witnessed the incident is urged to call 0800 151 0020 or email Rydehouse@ipcc.gsi.gov.uk.