Police have been given more time to question a second man arrested in connection with alleged arson attacks at properties connected to Sir Keir Starmer.
The 26-year-old was arrested on Saturday afternoon at London Luton Airport on suspicion of conspiracy to commit arson with intent to endanger life.
The arrest relates to three incidents: a vehicle fire in Kentish Town, a fire at the prime minister’s private home on the same street, and a fire at an address where he previously lived in north-west London.
On Sunday, a warrant of further detention was obtained at Westminster Magistrates’ Court, meaning the man can be detained for an additional 36 hours, the Metropolitan Police said.
Another man, Roman Lavrynovych, 21, who the BBC understands is a builder and roofer, appeared in court on Friday and is accused of three counts of arson with intent to endanger life following the fires.
He entered no pleas and was remanded in custody until a further hearing at the Old Bailey scheduled for 6 June.
The 26-year-old man is in police custody in London.
The Metropolitan Police’s Counter Terrorism Command has led the investigation because of the connection with a high-profile public figure.
Emergency services responded to a fire in the early hours of Monday at the Kentish Town home where Sir Keir lived before becoming prime minister and moving into 10 Downing Street.
Damage was caused to the entrance of the property, which it is understood Sir Keir still owns and rents out, but nobody was hurt.
On 8 May, a car Sir Keir sold to a neighbour in 2024 caught fire on the same street.
In the early hours of Sunday, firefighters dealt with a small fire at the front door of a house converted into flats in nearby Islington, where the prime minister previously lived.
One person was helped to safety via an internal staircase by crews wearing breathing apparatus, the fire brigade previously said.
