Can auditor purchase debentures of company in which he is appoint as auditor ?

As per Sec 141(3)(d)(i), if a person(auditor) or his partner or relative is holding any security (whether or not having voting rights) in the company or its subsidiary or its holding or associate company or a subsidiary of such holding co. then such person shall be disqualified from being appointed as auditor of the company.However, the relative of the auditor may hold securities for the face value not exceeding Rs. 1 lacs.

Please note: such exception only for relative and not for holding security by auditor or his partner.

Therofore,auditor  cannot hold debentures of auditee company.