The Madras High Court on Monday dismissed writ petitions moved by Member of Parliament from Sivaganga, Karti Chidambaram and wife Srinidhi Chidambaram against show-cause notices issued by the tax authority over an alleged non-disclosure of Rs 6.38 crores in income tax returns following a 2013 property sale (Karti P.Chidambaram v. The Principal Director of Income Tax and ors).