Los Amigos of Orange County issued a hand-delivered letter to Police Chief Roger Baker on Monday asking for his resignation.
Activists and police have been at odds over a city policy that allows INS officials to question suspects at the City Jail about their citizenship and immigration status.
The dispute escalated after activists learned that Baker had prepared an internal background report about them and presented his findings to the City Council.
The letter, signed by Los Amigos Chairman Amin David, reads in part:
"You misused investigative resources under cover of official secrecy. You targeted myself and hundreds of Anaheim friends and neighbors without legitimate cause to do so."