Former City Hall health and human services chief Felix G. Arroyo is suing Boston Mayor Martin J. Walsh, saying he was wrongfully fired three years ago in the wake of sexual harassment accusations that Arroyo denies. He is alleging that the city’s probe of that matter was “a sham from the beginning.”

In a civil complaint filed Friday in Suffolk Superior Court, Arroyo alleges breach of contract, negligence, and defamation, among other counts. He is claiming $390,000 in lost compensation to date, as well as $260,000 in “reasonably anticipated lost wages.” The suit names Walsh and the City of Boston as defendants.