Pc David Carrick, 47, an armed officer who served with the Parliamentary and Diplomatic Protection Command and worked on the parliamentary estate, faces a total of 53 charges – including 27 counts of rape.
He has already denied 44 offences relating to 12 women and faces trial at Southwark Crown Court in February.
Carrick is expected to appear at the Old Bailey on Tuesday afternoon over nine further charges against another woman in July 2003.
They include six counts of rape, one count of false imprisonment, one count of indecent assault and one count of possessing a firearm with intent to cause fear of violence.
He is charged with a total of 53 offences against 13 women between 2003 and 2020.
They include 27 counts of rape, nine counts of sexual assault, five counts of assault by penetration, three counts of coercive and controlling behaviour, three counts of false imprisonment, two counts of attempted rape, one count of attempted sexual assault by penetration, one count of causing a person to engage in sexual activity without consent, one count of indecent assault and one count of possession of a firearm with intent to cause fear of violence.