A fourth man who was arrested by police investigating fires at properties linked to Sir Keir Starmer has been released on bail.
The 48-year-old was stopped at Stansted Airport on Monday and arrested on suspicion of conspiracy to commit arson with intent to endanger life.
On Wednesday the Metropolitan Police said he had been released on bail to a date in July.
Three men have already been charged in connection with the fires: Ukrainians Petro Pochynok, 34, and Roman Lavrynovych, 21, and Ukrainian-born Romanian national Stanislav Carpiuc, 26, who are all due to appear at the Old Bailey on Friday.
Lavrynovych, of Sydenham, south-east London, is charged with three counts of arson with intent to endanger life.
Pochynok, of Holloway Road in Islington, north London, and Carpiuc, of Chadwell Heath, east London, are accused of conspiring to commit arson with intent to endanger life.
Two of the fires took place in Kentish Town, north London – one in the early hours of May 12 at the home where Sir Keir lived before he became Prime Minister and moved into Downing Street.
A car was set alight in the same street four days earlier on May 8.
The other fire took place on May 11 at the front door of a house converted into flats in Islington.
