Repubblika organised a small protest in Birkirkara on Friday, using two vehicles with loudspeakers to convey a message.
"We have a justice minister who is servile to criminal millionaires," Repubblika President Robert Aquilina said.
During the press conference, Aquilina said that when Minister Edward Zammit Lewis got to know that Yorgen Fenech was the owner of 17 Black, he kept an "intimate relationship" with him.
The NGO called on Prime Minister Robert Abela to fire Edward Zammit Lewis as soon as possible.
Aquilina said that Zammit Lewis should not be holding a public post.
The messages which were published in the press recently, he said, showed that Zammit Lewis was doing "all that he could" for Fenech to pay attention to him and continue their friendship.