Giving clean chit to ex-SEBI chief Madhabi Puri Buch on Hindenburg's claims, Lokpal said complainants TMC MP Mahua Moitra, senior advocate Prashant Bhushan and ex-IPS officer Amitabh Thakur approached it with "unclean hands". It said they tried to "abuse Lokpal's process" and complaints "purely for political reasons". "Complaints filed to keep issue alive after media campaign failed," it added.