British police have reported a 10th arrest in their investigation into a massive jewel heist at Graff Diamonds' flagship store in London.

Scotland Yard says it has arrested a 45-year-old man at his north London home on suspicion of helping plot the $65 million robbery.

Thursday's announcement brings to 10 the number of people arrested in connection with the Aug. 6 theft of rings, bracelets, necklaces and watches from Graff Diamonds on Bond Street.

Police say two men walked into the store, pulled out guns, briefly took an employee hostage and escaped with the jewels in a series of getaway cars.

Eight others have been charged with conspiring to rob the jeweler. A ninth suspect has been released on bail and has not been charged.