Audit by a ca who is not an employee/partner: billing

Hello,

A Chartered Accountant named 'Tendulkar' has his own proprietory firm 'Tendulkar & Associates'. A friend of him 'Kambli' who is also a Chartered Accountant but works as a Professional Consultant in some firm(also holds COP) refers a relative of him to get his accounts audited by 'Tendulkar'. However, to reduce the fees, Kambli offers to help Tendulkar in his work and Kambli is the one who signs the Income Tax Audit and VAT Audit.

Now, can 'Tendulkar & Associates' invoice the client for his Audit Fees? FYI, Kambli is neither a partner nor an employee of Tendulkar.