A 23-year-old woman has been charged with conspiracy to commit robbery and kidnap in connection with the £53m Securitas depot robbery in Kent.
The £53m Securitas raid was the UK's largest cash robbery
Katie Louise Philp, from Tonbridge, was one of four people arrested in the past two days.
A man from south-east London is being questioned over conspiracy to rob.
A woman, 22, held in Woodford, Essex, over assisting offenders and a man, 29, from Bromley, held over conspiracy to rob and kidnap, have both been bailed.
Detectives believe they have recovered £21m of the stolen cash and that another £30m is probably hidden somewhere in south-east England.
Speaking on Friday, Kent Police Chief Constable Mike Fuller said 36 people had been arrested in total.
Eight people have already been charged and police are seeking the extradition of a man arrested in Morocco.
The raid on the Securitas depot was Britain's biggest ever cash robbery.