Fourth man arrested at airport over firebomb attacks at properties linked to Keir Starmer in north London

The Met Police said a man, 48, was arrested on Monday at London Stansted Airport.

The force said: "He was initially stopped by officers under schedule 7 of the Terrorism Act, 2000, before being arrested on suspicion of conspiracy to commit arson with intent to endanger life.

"The arrest is connected to an investigation into a vehicle fire in NW5 on Thursday, 8 May, a fire at the entrance of a property in N7 on Sunday, 11 May and a fire at a residential address in NW5 in the early hours of Monday, 12 May."

The man has been taken to a London police station - where he remains in police custody.

The Crown Prosecution Service previously authorised charges against three other men:

• Roman Lavrynovych, 21, of Sydenham, a Ukrainian national was charged with three counts of arson with intent to endanger life.
• Stanislav Carpiuc, 26, of Romford, a Romanian national, was charged with conspiracy to commit arson with intent to endanger life.
• Petro Pochynok, 34, of north London, a Ukrainian national was charged with conspiracy to commit arson with intent to endanger life.

It comes after reports authorities are investigating whether Russian operatives recruited three Ukrainian-born men charged with arson or conspiracy to commit arson.

Roman Lavrynovych, 21, an aspiring model from Ukraine, living in Sydenham, south London, was charged with three counts of arson with intent to endanger life.

Petro Pochynok, 34, from Holloway, north London, describes himself online as a fashion entrepreneur, was charged with conspiring with his two co-defendants, as well as “with others unknown”, to commit arson.

Stanislav Carpiuc, 26, a fellow aspiring model, is a Russian-speaking Romanian citizen born in Ukraine. He was charged with conspiracy to commit arson with intent to endanger life.

Russia has denied any connection with the arson attacks or the three men, describing the claims as "false, unsubstantiated" and "ridiculous".

The Kremlin added: "London seems to think that Russia is behind all the bad things that happen in England."

All the men have connections with a high-profile public figure, according to the Met police, and so the Met’s Counter Terrorism Command is leading the investigation into the fires.

Sir Keir Starmer told the House of Commons the arson attacks were "an attack on all of us, on democracy and the values that we stand for".

Counter-terrorism officers worked "at pace" to establish the cause of the fires and "any potential motivation", Scotland Yard said.

The fires took place at properties and a car linked to the Prime Minister.

The car, which Starmer had sold to a neighbour last year, was set on fire, before a fire was set to a building the Prime Minister is understood to have lived in the 1990s.

Neighbours described hearing a loud bang and said police officers were looking for a projectile.

Pochynok was arrested on Monday, 19 May, in the Chelsea area of London, on suspicion of conspiracy to commit arson with intent to endanger life.

Pochynok appeared at Westminster magistrates’ court on May 21.

Lavrynovych and Carpiuc have both appeared at Westminster Magistrates’ Court, and have been remanded in custody.