Mark Kingon has been appointed the new acting commissioner for the South African Revenue Service (SARS), the Treasury announced on Tuesday morning.

This follows the suspension with immediate effect by President Cyril Ramaphosa of current commissioner Tom Moyane on Monday night. (Read Ramaphosa's letter suspending Moyane in full here.)

Kingon stepped into the role of second in charge in an acting capacity at SARS last week when chief officer for business and individual taxes Jonas Makwakwa resigned.

The Treasury said in a statement on Tuesday morning that Kingon had been with SARS since its establishment and worked his way through the ranks to become the group executive for relationship management within business and individual taxes.

Ramaphosa cited among his reasons for suspending Moyane the deterioration in public confidence in SARS and public finances being compromised due to the ongoing controversy at the tax agency under Moyane’s leadership.

Ramaphosa said it was in the public interest to restore the credibility of SARS without delay.

In a letter to Moyane, Ramaphosa said: "For the sake of the country and the economy, this situation cannot be allowed to continue, or to worsen."

Ramaphosa said Moyane held a high position "of trust in managing the countries finances".

"It was therefore necessary to act urgently and immediately to protect the institution and place it on a path to stability and recovery," the presidency said in a statement.

Ramaphosa suspended Moyane after a meeting with him in which he informed him that he had "lost confidence in his ability to lead SARS".

Ramaphosa offered Moyane an opportunity to resign with immediate effect, which, according to the presidency statement, Moyane declined.

In the statement, the presidency said concern was raised about the way Moyane handled the issue of his second in charge, Jonas Makwakwa, and Moyane’s failure to immediately report this to the finance minister.

Another issue of concern was the management of tax refunds — a tax ombudsman finding.

This potentially jeopardised SARS as a collector of revenue and affected tax morality, the presidency said.

Earlier Business Day reported that Moyane had refused to step down after he was asked to resign by Ramaphosa.

Pressure has been building for Moyane to quit. Factors include a R48bn hole in revenue collection and his leadership and handling of the allegations against Makwakwa, which has come under increased scrutiny by Parliament’s standing committee on finance.

This comes on the cusp of an announcement by Moody’s on Friday on whether SA’s investment status will be downgraded.

SARS on Monday issued a statement saying that Moyane was being vilified unnecessarily by the media.

Moyane last week announced the resignation of Makwakwa, after the SARS commissioner had shielded him for more than a year. Moyane was presented with a Financial Intelligence Centre report into suspicious and unusual transactions into Makwakwa’s personal bank accounts and that of his partner Kelly-Ann Elskie in May 2016. After a year-long investigation by international law firm Hogan Lovells, Makwakwa was cleared of all charges and returned to work after being suspended for more than a year.

Makwakwa resigned last week after it was revealed that one of the companies channelling money into his personal bank accounts was appointed as a debt collector by SARS.