The two women keeping a tight leash on Kenya's purse holders

"I am the only state officer in my institution so there is nothing like confusion there. So I asked them why is the budget showing three times what my annual salary is. And it was like that for all the state officers. I have not received the answer to date."

The statement came months after she told Parliament how she was put under duress by state officials, including former National Treasury Cabinet Secretary Ukur Yatani, to authorise billions of shillings in withdrawals weeks to the 2022 General Election.

One of the transactions she flagged, the Sh6 billion nationalisation of Telkom Kenya, was blocked and is currently the subject of a probe by the Ethics and Anti-Corruption Commission.

That is just one of many multi-billion requisitions that Nyakang'o has blocked from the exchequer because the state agencies or counties seeking the funds have flouted public finance protocols.

She has over three decades of experience in finance and accounting and her Doctorate in Business Administration from the University of Liverpool, UK focused on strategic workforce planning in the Kenyan public service.

This experience has stood her in great stead as she heads one of the key offices that works to check and report on public spending.

At a time when the economy is in a rut and with a new administration settling in, Nyakang'o has on several occasions highlighted the pitfalls that undermine effective public spending.

This she does with an eloquence that displays her understanding of her office's function and the loopholes in the law governing public finance that are exploited to facilitate the embezzlement of public funds.

"If employees are not sure whether they will be employed tomorrow, they of course try to gather as much as possible so they can run away," she explained during a past interview. "If employees are insecure these issues will create uncertainty and that causes loss of integrity."

Nyakang'o was appointed in December 2019 and succeeded Agnes Odhiambo, who was Kenya's first Controller of Budget under the new constitution.

Ms Odhiambo spent a big part of her term in office setting up shop in all the 47 counties and guiding them on building their budgeting systems to best practice.

Nyakang'o's term on the other hand, currently on its halfway mark, has seen the Office of the Controller of Budget broaden its oversight role leading to audit reports that have raised pertinent questions such as the nature of public debt and the limits of the Executive in drawing supplementary budgets.

"I have been approving payments of public debt and I have looked at what we are paying for and many of those things cannot be identified," said Nyakang'o in a past interview.

"You just find a name of why we borrowed, you cannot trace it to anything or tell what the money was spent for and therefore there is no economic gain from that borrowing."

In probing the true nature of Kenya's Sh11 trillion stock of public debt, Nyakang'o is in sync with her counterpart, Auditor General Nancy Gathungu whose office is the second line of defence of taxpayers' funds.

Appointed in July 2020 at the peak of the Covid-19 pandemic, Ms Gathungu replaced the first Auditor General Edward Ouko.

Ouko's term in office was marked by high-profile wrangles with government officials in the Jubilee government who detested the new scrutiny into how they spent public funds.

Gathungu's first order of business saw her thrust into the scandal involving the Kenya Medical Supplies Agency (Kemsa) and its use of billions of funds for Covid-19 intervention.

In a special audit report, Gathungu revealed that Kemsa had irregularly issued Sh7.7 billion in commitment letters to various suppliers and more than Sh4.7 billion already paid out by the time the scandal was unearthed.

The report also revealed that some firms that had been in existence for less than a year won Sh1.2 billion in tenders, an indication of the age-old scam of using brief-case companies for procurement fraud.

A Certified Public Accountant and a Certified Information Systems Auditor, Gathungu holds a Master of Business Administration in Strategic Management and a Bachelor of Commerce in Accounting.

Her small stature and quiet demeanor belies her diligent drive and attention to detail, cultivated over 30 years in the civil service - which can sometimes be gleaned from her piercing eyes.

"The constitution speaks to 12 months in a financial year, but we have created a 13th month and in that month there is a lot of wastage of resources," she said during a conference last year that President William Ruto attended.

"Accounting officers struggle to absorb funds in May, June and unfortunately in July, funds they should not be receiving in July," she said.

"This creates the loopholes for wastage, re-alocation, misalocation, illigalities and irregularities."

Last year, the Auditor General revealed that more than Sh147 billion spent by the national government in the past financial year was unauthorised and that the National Treasury backdated more than Sh100 billion in expenditure for the financial year ended June 2022.

"The CS National Treasury needs to address this and this can be done as a directive or as an amendment to the Public Finance Management Act including introducing accrual accounting so that PSs do not struggle as others have struggled before to absorb funds at the last quarter of the financial year," explained Gathungu.

The Controller of Budget and Auditor General form a crucial line of defence against corruption and wastage of public funds.

It is not surprising that both women, halfway into their eight-year terms, are facing unprecedented challenges that threaten to remove them from office.