It is hereby made the duty of every person engaged in the business of supplying gas service for compensation for any purpose to file with the city clerk on the first day of September of each year, a sworn statement of the gross receipts of such person from such business for the twelve (12) months ending on the thirtieth day of June preceding the filing of such statement. The director of finance of the city shall be, and is hereby authorized to investigate the correctness and accuracy of the statement required and for that purpose shall have access at all reasonable times to the books, documents, papers and records of any person making such statement in order to ascertain the accuracy thereof.

(Code 1964, § 11-220)