In a series of cases, the Thane police have registered a case against a couple and their son for allegedly cheating a builder of nearly Rs 42 lakh in a land sale deal. Meanwhile, the Navi Mumbai police have arrested a director of the APMC at Vashi in connection with a corruption case involving a contract to build toilets. Additionally, a case has been registered against four persons for fraudulently transferring Rs 47.6 lakh from the account of the Maharashtra School Education and Sports Department using forged cheques.