Police from Fairlop, Fullwell and Clayhall Safer Neighbourhood Teams joined forces with border immigration staff from Belfast on an operation to detain a wanted man.
Officers headed to Forest Road, Hainault to search for Sorin Popescu, who had been sentenced in his absence to 14 months imprisonment for assisting with illegal entry into the UK.
A Met Police spokesman said after police entered Popescu's home on Tuesday, July 29, they conducted a sweep of the property.
"During an extensive search, large quantities of a white unknown powder believed to be class A controlled drugs (which included a sack amounting to 5/10kgs) were seized.
"Popescu was further arrested for possession with intent to supply.
"During the search a firearm was also found and he was further arrested for possession of a firearm - scenes of crime officer attended and made the gun safe and removed it."
Police said the white powder has been sent to a lab for tests and the firearm will also be examined in more detail.
"Following questions in interview, the male was transferred to Coventry for court appearance by Serco before starting his prison sentence."
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