Second ADF member charged over robbery

A second Australian Defence Force member has been arrested over an armed robbery at a Sydney air base credit union two years ago.

It's alleged the 24-year-old and another female ADF private threatened a female employee with a gun at RAAF Base Richmond before fleeing with cash during the February 2014 robbery.

The woman, who is a serving member of the ADF based in Victoria, handed herself in to Sydney's Surry Hills police station on Thursday and has been charged with three offences, including possession of a prohibited firearm.

She was refused bail and was due to appear in Central Local Court on Friday afternoon.

Her alleged accomplice, Tayla Stahl, 21, was last week remanded in custody after being charged over the robbery.

The private is due to return to court in June.