The prime minister’s sister-in-law has said she feared what might have happened had she not woken up after her home was targeted in an arson attack, a court has heard.

The incident is one of a series of arson attacks that took place in May last year on property linked to Keir Starmer, which three men with links to Ukraine are accused of targeting. They deny all the charges.

Roman Lavrynovych, 22, and Petro Pochynok, 35, both from Ukraine, and Stanislav Carpiuc, 27, a Romanian national, appeared at the Old Bailey on the second day of their trial as jurors heard how Judith Alexander became aware of the fire in the early hours of 12 May last year.

“All of a sudden, I heard two bangs. It was very loud and sounded like two wheelie bins had been thrown at the door,” said a statement read to the court. “I did not see anyone on the street but when I looked down I saw smoke and an orange glow where the front door was.”

Alexander told the court she had moved into the Kentish Town property in north London in 2024, after Starmer moved to Downing Street. Before the fire had broken out, she had been lying awake in bed on her phone as her partner and daughter slept.

The court heard how Alexander called the fire brigade and attempted to “frantically” call her sister Victoria, Starmer’s wife. Her daughter’s bedroom was near the fire and she was woken up by the smoke, the statement said. Alexander gave them all Covid masks to wear.

“We could see the smoke was getting thicker and going upstairs,” said Alexander, and described her daughter as “really frightened” and “extremely worried”. Alexander has asthma and struggled to breathe as the house filled with smoke, the court heard.

It was only after the fire brigade had attended that the “realisation of what happened really hit me,” she added. “The fact that [my daughter’s] room was right above the fire and if I did not wake up, what might have happened. I was awake all night.”

The incident followed two others that occurred last May, when police were called to a fire at a house in Islington, north London, connected to Starmer and a blaze involving a car that also once belonged to the prime minister.

Lavrynovych faces three counts of arson with intent to endanger life or being reckless as to whether life would be endangered. Pochynok and Carpiuc are also accused of conspiracy to commit arson.

The court heard the 22-year-old was arrested in south London on 13 May last year. During a search, a petrol can and a bottle of white spirit were seized and were found to have the defendant’s DNA on them.

In a police interview after his arrest, Lavrynovych denied being involved in the fires and claimed he was at home on the dates of the first two incidents and visiting a friend in Camden on the third, according to the prosecution. When asked if someone had asked him to start the fires, Lavrynovych said: “I think you need to speak to a different person.”

When asked who, he replied: “I don’t know, I never saw this person.”

When asked by the officer whether someone asked him to set fire to the three addresses, Lavrynovych allegedly replied “yes”.

It is alleged the three men with links to Ukraine were offered payment to set fire to a car and two houses linked to Starmer by a Russian-speaking Telegram contact named El Money – a translation of the Ukrainian word “Hroshi”.

On 8 May, a Toyota RAV4, once owned by Starmer before he sold it to a neighbour, was set ablaze. Another fire took place on 11 May at the front door of a property in Islington, north London, which Starmer had previously managed.

A third fire was set in the early hours of 12 May outside the Kentish Town home where Starmer lived before he moved into Downing Street, and where his sister-in-law was now living.

On Wednesday, the court heard that Telegram messages recovered by the police between Lavrynovych and El Money showed he had been recruited, instructed and promised payment in cryptocurrency for the fires. Pochynok had been recruited by Carpiuc to help Lavrynovych with the first fire, while Carpiuc’s role involved planning and receiving payment.

In a prepared statement, Lavrynovych said El Money had offered him £1,500 to check for CCTV in the area and had given instructions about the two addresses, the court heard.

Lavrynovych “needed the money”, though he had not been paid, the court heard. He said he “felt threatened” as El Money said he “would have to do the job as he knew where I lived”, the court heard. Lavrynovych said he was “scared” as his grandmother shared his address.

Lavrynovych said he “did not commit arson at any address”.

The trial is expected to last three weeks.