Prosecutors say the pair covertly filmed Winehouse and sold the footage to The Sun newspaper. In January the paper published the images, which appeared to show the singer smoking crack cocaine.
Detectives decided there was not enough evidence to charge Winehouse but they charged the couple.
Prosecutor Sean Larkin says police who raided the couple's home found a list of celebrities they supplied with drugs, including Winehouse.
A judge ordered the couple to return Nov. 28 for sentencing.