According to the report, Erman used his phone to record conversations among coaches and players without their knowledge, sometimes leaving his phone in a room to capture conversations when he was not physically present.
"As previously stated, Darren Erman was terminated due to a violation of company policy," the Warriors said in a statement. "We were unaware of the violation, and when made aware, we took immediate action. We will have no further comment at this time."
California, where the Warriors are based, has what is known as a "two-party consent" wiretapping law, which requires the consent of all parties to record a private conversation.
When Erman was caught, he allegedly told the Warriors he had been recording them for three weeks. He was fired on April 5.
Erman has since been hired by the Boston Celtics as director of NBA scouting, according to Yahoo Sports.
The case is the second recent incident of secret recordings within the NBA -- the league is expected to make an announcement today regarding a recording attributed to LA Clippers owner Donald Sterling, who allegedly makes racist remarks on the secret tape.