Article 96-3 of the Penal Code
(1) A person who by the use of fraudulent means or force commits an act which impairs the fairness of a public auction or bid, shall be punished by imprisonment with work for not more than 2 years or a fine of not more than 2,500,000 yen.
(2) The same shall apply to a person who colludes for the purpose of preventing a fair determination of price or acquiring a wrongful gain.