Tharaka Nithi Governor Samuel Ragwa is under investigation over 'forged' payment vouchers presented to the Senate Public Accounts and Investments committee.
The Auditor General told the Senate on Thursday that the governor only presented photocopies instead of originals in all bank and county suspicious transactions.
"What we have managed to get from the county is only photocopies so we can not ascertain the authenticity of these vouchers," the Auditor General said.
Governor Ragwa had last week appeared before the Senate but could not account for Sh1.2 billion shillings including Sh111 million meant for health services.
The governor was ordered to come with documents to account for the money, but the one week period given to him was the point of contention with a section of senators claiming the governor "used that time to manufacture receipts".
Kiambu senator Kimani Wamatangi said governors have mastered the art of evading audit queries by forging vouchers to balance the books.
"I am opposed to giving this governor more time because they will go manufacture receipts and bring to us here, what will we be doing as the Senate," Wamatangi said.
Nyandarua Senator Muriuki Karue questioned why the governor did not produce original receipts to the auditors.
"I hate liars these are manufactured receipts but let me just have a look at them," Karue said.
"There is a very serious matter here not one but three Senators have asked you governor about manufactured receipts but you seem unconcerned, it will be very simple for us," Kakamega Senator Bony Khalwale said.
However the governor who was hard pressed by the committee defended himself saying the receipts were authentic and they will produce more.
"On this matter of manufactured receipts we do not do that as a county, we have provided vouchers and they are all here," Governor Ragwa told the committee.
Committee chair Anyang' Nyong'o said they will no longer subject auditors back-and-forth over the missing vouchers, but they will proceed and write the report, and make far-reaching recommendations.
Nyongo said Tharaka Nithi was the only county with "an encyclopedia" of audit queries, totaling 51.