72. Best Judgment Assessment

If any person, liable to pay service tax -

(a) fails to furnish the return under section 70;

(b) having made a return, fails to assess the tax in accordance with the provisions of this Chapter or rules made thereunder, the Central Excise Officer, may require the person to produce such accounts, documents or other evidence as he may deem necessary and after taking into account all the relevant material which is available or which he has gathered, shall by an order in writing, after giving the person an opportunity of being heard, make the assessment of the value of taxable service to the best of his judgment and determine the sum payable by the assessee or refundable to the assessee on the basis of such assessment.