Who audits the Auditor?

As per the consultation paper Efficacy of Public Audit System in India: C & AG – Reforming the Institution, "In India there is no external audit of C&AG's outfit. In practice C&AG nominates one of the Accountant General under him as an auditor for C&AG's office. This is not a very satisfactory arrangement. Commonwealth countries such as U.K and Australia have made legal provision not only for audit of National Audit Office by independent auditors but scrutiny of budget estimates by a parliamentary committee which oversees its functioning. It is for consideration whether an external audit arrangement be made C&AG's set-up in line with the practice in UK."

In United Kingdom, Public Accounts Commission, a commission of MPs approves the budget of the National Audit Office(NAO), Appoints the non executive board members, scrutinizes costs and performance, appoints external auditor of NAO, commissions value for money studies of NAO operations. 

The role of the Public Accounts Commission is defined by the National Audit Act 1983 and the Budget Responsibility and National Audit Act 2011. 

There is a need for external audit of the supreme audit institution of the country that is C&AG in India. This will not only improve the transparency within the organization but it will also be comparable with the practice worldwide. 

Source: 

https://www.nao.org.uk/about-us/wp-content/uploads/sites/12/2013/02/Introduction-National-Audit-Office.pdf

http://www.parliament.uk/business/committees/committees-a-z/other-committees/public-accounts-commission/role/