Police have arrested nine people in total as part of their probe
Two organisations are no longer being investigated as part of a City Hall fraud inquiry, police have said.
The European Federation of Black Women Business Owners and the Desh-Bangla Foundation were among six groups investigated by detectives.
All the groups received funding from the London Development Agency (LDA), the mayor of London's business arm.
Nine people have been arrested as part of the fraud investigation. All have been released on bail.
The latest arrest was of a 36-year-old man, who attended Belgravia police station on Tuesday.
He was held on suspicion of aiding and abetting misconduct in a public office before being released on bail.
Former mayor Ken Livingstone's race adviser Lee Jasper resigned amid allegations over the misuse of public funds.
An internal inquiry in January cleared him of any wrongdoing, but he was suspended by the mayor pending the police investigation.