A 31-year-old man was arrested at an address in north-west London this morning (Friday, 9 May) as part of the investigation, which is being led by the Met’s Counter Terrorism Command.
The man, who is an Iranian national, was arrested and detained under section 27 of the National Security Act 2023.
Three men, aged 39, 44, and 55, were arrested on Saturday, 3 May as part of the investigation. Warrants of further detention have been sought and obtained for them today, meaning the three men can be detained until Saturday, 17 May.
As part of this investigation, searches were also carried out at two addresses in north-west London, on Friday, 9 May. The searches are now complete.
This investigation is not connected to the arrest of five people on Saturday, 3 May as part of a separate Met Counter Terrorism operation.
Enquiries remain ongoing.
The original announcement can be found here.