A suspected Albanian gangster carrying a loaded pistol and silencer has been arrested outside the home of former Prime Minister Tony Blair, police have said, Sky News reported.

There was no threat to Blair's safety, it is understood.

The suspect, 56, was stopped in his car as he drove in Connaught Street, central London, on Monday at 11.15 p.m. local time.

Officers on patrol became suspicious and arrested him for alleged traffic and documentation offences.

About 25 minutes later, a passer-by approached a uniformed officer on guard outside Blair's £3.5m Connaught Square townhouse.

He handed the officer a black pistol, loaded with several bullets and fitted with a silencer, saying he found it in the gutter.

The officer raised the alarm and notified members of the Diplomatic Protection Group, who are responsible for Blair's safety.

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