At about 01:40hrs on Wednesday, 20 December officers became aware of a car on The Hyde, NW9.
A man ran from the car and then entered an area of water known as The Silkstream and made his way to the far bank, where he was then seen to collapse.
Officers did not follow him into the water, but made their way around water’s edge to try and reach him.
The area where the man collapsed was enclosed by fences and despite all attempts officers could not reach him.
London Fire Brigade (LFB) and London Ambulance Service were called to the scene.
LFB used specialist equipment to assist in reaching the man and first aid was administered.
LAS took the man, believed to be in his late 40s, to hospital in a critical condition. He sadly died in the early hours of the morning (20 December).
His next of kin have been informed and are being supported by specialist officers.
As in all cases of death following police contact, the Met’s Directorate of Professional Standards have been informed.
A mandatory referral has been made to the Independent Office for Police Conduct.
The officers involved are being supported following the traumatic event.

Commander Owain Richards of the Met’s Frontline Policing said: “This is a very sad incident and my thoughts and condolences go out to the man’s family and all those affected.

“It is only right and proper that all the circumstances surrounding this incident are fully investigated and the Met police will fully cooperate with any inquiry.

“In the meantime, we will be speaking to our partners and the community to provide reassurance and provide as much information as we can.”