Seven suspects, aged between 48 and 76, landed in the police net for conspiracy to burgle 'Hatton Garden safety deposit' after a series of raids on 12 different areas in London and adjoining places.
Another two, aged 43 and 58, were arrested later in the capital. All nine remain in custody.
A "significant amount of high-value property" have been recovered by officers which they believe was stolen during "the raid on the safe deposit company over the Easter bank holiday."
"This morning detectives from the Flying Squad arrested men aged between 48 and 76 for conspiracy to burgle and recovered a large amount of property," Scotland Yard said.
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More than 200 officers carried out raids in across 12 addresses in London and Kent.
Following the heist, media reports said that diamonds, jewels and cash worth tens of millions of pounds were stolen during the night of April 3, at the start of the Easter bank holiday weekend.
The Met has faced criticism over the raid, particularly after it emerged that police did not respond to a burglar alarm at the scene.
In a statement, Commander Spindler said, "The Metropolitan Police takes these types of crimes very seriously.
"At times we've been portrayed as if we have acted like Keystone Cops but I want to reassure you that in the finest traditions of Scotland Yard, these detectives have done their utmost to bring justice to the victims of this callous crime.