Six people are still being held after raids across London

This article is more than 8 years old

This article is more than 8 years old

One of seven people being held in an investigation into a suspected terror plot has been released without charge.

A 30-year-old woman who was arrested at an address in Ealing, west London, on Thursday was freed by police on Saturday.

Officers continue to hold six people in custody at a south London police station, including a 22-year-old woman who was arrested in Hackney, east London, early on Saturday.

She was detained on suspicion of the commission, preparation or instigation of acts of terrorism under the Terrorism Act 2000, a spokesman for the Metropolitan police said.

The arrest, by officers from the Met's counter-terrorism command, follows six others made on Thursday.

The British Muslim convert Richard Dart, 29, is reportedly one of the six arrested over the suspected terror plot. Dart, who changed his name to Salahuddin al-Britani after converting, is believed to have been one of three people detained in Ealing, where he was arrested in the street.

He appeared in a BBC3 documentary, My Brother the Islamist, made by his stepbrother Robb Leech last year, which described how Dart, originally from Weymouth, Dorset, had been converted by the controversial cleric Anjem Choudary. In the documentary he spoke of his support for jihad and sharia law.

The others detained in Ealing were a 21-year-old man and the now-released 30-year-old woman, held at separate home addresses.

Three men living just over a mile from the Olympic site in Stratford, east London, were also arrested. The men, aged 18, 24 and 26, believed to be members of the same Bangladeshi family, were detained in a raid on their home.

The six are being held on suspicion of the commission, preparation or instigation of acts of terrorism. Warrants of further detention were granted at Westminster magistrates court on Saturday.

The alleged plan involved Islamist extremists with potential targets in the UK, but was not linked to the Olympics or Paralympics, it is understood.

The threat to the UK from international terrorism is rated substantial – the third-highest of five levels.