The incident happened at Whetstone after police were called to a report that a man was damaging a car.
The report was delivered at 1.08pm saying that a man had been throwing bottles at traffic and one had hit a car.
Two officers traced the man, later named as Ziya Mustafa Bitirim, from north London, and were reportedly attempting to arrest him when he collapsed.
After the officers and an ambulance crew failed to revive Mr Bitirim he was taken to Barnet General hospital where he was pronounced dead.
A spokesman for the Police Complaints Authority said last night that it had begun an investigation after having had the matter referred to it by the Metropolitan force.
A post-mortem examination last night at Finchley Memorial hospital into Mr Bitirim's death proved inconclusive and further tests are being carried out today.
Brigadier Anthony Vivian, of the PCA, said the inquiry would be headed by Superintendent Michael Partington of the Metropolitan Police Complaints Investigation Bureau.
He added: "A full investigation will be carried out and the detailed results prepared for the coroner's inquest."
A Scotland Yard spokeswoman said that Mr Bitirim was being arrested for breach of the peace and for his own safety when he collapsed.Reuse content