Public Protector Busisiwe Mkhwebane is a step closer in her attempt to establish how former South African Revenue Service (Sars) deputy commissioner Ivan Pillay took early retirement and then ended up back at the tax man in a senior position.

More than a week ago, the Public Protector subpoenaed Pillay, former Sars commissioner Oupa Magashula, and senior Sars official Vlok Symington to appear before her in connection with Pillay's retirement, pension payout and reemployment at Sars, her spokesperson, Oupa Segalwe, told News24.

Magashula left Sars in 2009 and Pillay in 2015.

Sars was under the spotlight for mass resignations and changes to job descriptions following former commissioner Tom Moyane's controversial plans for sweeping changes at the receiver.

Pillay had been allowed to take early retirement in 2010 on condition the pension fund was topped up to make up for the shortfall of an early retirement.

He returned to Sars in the same year on a contract.

Legal specialist Symington, also claimed he was held hostage at Sars' Pretoria offices by Hawks members and Moyane's bodyguard, Thabo Titi.

The incident involved alleged attempts to coerce Symington to hand over an email related to Pillay's early retirement.

Segalwe told News24: "Yes, they did [appear]" and that the "meetings went well".

The spokesperson added that he could not comment any further because the meetings were "part of an ongoing investigation".

"There are no outcomes to share at this stage, lest we jeopardise the investigation," Segalwe said.

The subpoenas follow an anonymous request to the Public Protector to investigate the issue.

In an explanatory statement released in November last year, Mkhwebane stated that she had written to former finance minister and now Public Enterprises Minister Pravin Gordhan four times to respond to allegations that he irregularly approved Pillay's retirement, bought off his pension balance and later allowed him to be reemployed by Sars in 2010.

On October 2 last year, Mkhwebane subpoenaed Gordhan to appear before her on November 14 after he allegedly failed to respond.