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 on Thursday was freed by police yesterday.
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 yesterday.
She was arrested 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.
British Muslim convert Richard Dart, 29, is reportedly one of the six people 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, west London, where he was arrested in the street.
He appeared in a BBC Three 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 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, who are believed to be members of the same Bangladeshi family, were detained in a raid on their home.
The six are all being held on suspicion of the commission, preparation or instigation of acts of terrorism.
Warrants of further detention were granted at Westminster Magistrates Court yesterday.
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 currently rated substantial - the third highest of five levels.