A highly respected police officer has shaken South Africa's government - and won the admiration of many ordinary people - with his explosive allegations that organised crime groups have penetrated the upper echelons of President Cyril Ramaphosa's administration.

Gen Nhlanhla Mkhwanazi did it in dramatic style - dressed in military-like uniform and surrounded by masked police officers with automatic weapons, he called a press conference to accuse Police Minister Senzo Mchunu of having ties to criminal gangs.

He also said his boss had closed down an elite unit investigating political murders after it uncovered a drug cartel with tentacles in the business sector, prison department, prosecution service and judiciary.

"We are on combat mode, I am taking on the criminals directly," he declared, in an address broadcast live on national TV earlier this month.

South Africans have long been concerned about organised crime, which, leading crime expert Dr Johan Burger pointed out, was at a "very serious level".

One of the most notorious cases was that of South Africa's longest-serving police chief, Jackie Selebi, who was sentenced to 15 years in prison in 2010 after being convicted of taking bribes from an Italian drug lord, Glen Agliotti, in exchange for turning a blind eye to his criminal activity.

But Gen Mkhwanazi's intervention was unprecedented - the first time that a police officer had publicly accused a cabinet member, let alone the one in charge of policing, of having links to criminal gangs.

The reaction was instantaneous. Mchunu dismissed the allegations as "wild and baseless" and said he "stood ready to respond to the accusations", but the public rallied around Gen Mkhwanazi - the police commissioner in KwaZulu-Natal - despite the province also being Mchunu's political turf.

#HandsoffNhlanhlaMkhwanazi topped the trends list on X, in a warning shot to the government not to touch the 52-year-old officer.

"He's [seen as] a no-nonsense person who takes the bull by the horn," Calvin Rafadi, a crime expert based at South Africa's University of Johannesburg, told the BBC.

Gen Mkhwanazi first earned public admiration almost 15 years ago when, in his capacity as South Africa's acting police chief, he suspended crime intelligence boss Richard Mdluli, a close ally of then-President Jacob Zuma.

Mdluli was later sentenced to five years in jail for kidnapping, assault, and intimidation, vindicating Gen Mkhwanazi's view that he was a rotten apple within the police service.

Gen Mkhwanazi faced enormous pressure to shield Mdluli, with his political bosses assuming that the officer, aged only 38 at the time, would be "open to manipulation [but] they were grossly mistaken", said Dr Burger.

Not only did he push ahead with Mdluli's suspension, he also made claims of political interference during an appearance in Parliament.

While this move earned him brownie points with citizens, his public outburst did him no favours and he was axed barely a year into the job and shunted back into obscurity for a number of years.

He made a dramatic comeback in 2018 when then-Police Minister Bheki Cele appointed him to the provincial police chief post, with one of his major tasks being to investigate killings in a province where competition for political power - and lucrative state tenders - is fierce.

It would be the disbandment of this investigative unit by Mr Mchunu that led to Gen Mkhwanazi's explosive briefing a fortnight ago, complaining that 121 case dockets were "gathering dust" at the national police headquarters.

"I will die for this [police] badge. I will not back down," Gen Mkhwanazi said, in line with his reputation of being a brave and selfless officer who cannot be captured by a corrupt political and business elite.

A survey by the Human Sciences Research Council (HSCRC) shows that public trust in the police stands at an all-time low of 22%,

The police force has long been plagued by issues of political interference, corruption and a seeming inability to effectively tackle the high crime levels.

The crisis has also reached the force's upper structures, with about 10 different police chiefs since 2000 - one has been convicted of corruption and another currently faces criminal charges.

"The dysfunction is across all levels," Gareth Newham of the Pretoria-based Institute for Security Studies (ISS) think-tank told the BBC, adding that "there are many dynamics within the police service that need to be fixed".

But Gen Mkhwanazi's tenure has not been without controversy. He was the subject of an investigation by the police watchdog, following a complaint that he interfered in a criminal investigation into a senior prisons official.

However, he was cleared of the charge last month, with the opposition Economic Freedom Fighters (EFF) saying the complaint was "designed to derail a committed officer who has been unrelenting in his fight against crime and corruption".

Gen Mkhwanazi's team has also faced criticism for their heavy-handed approach towards criminal suspects, who are sometimes shot dead in confrontations with officers under his command.

Mr Newham said that with Gen Mkhwanazi seen as the "cop's cop", the public was willing to turn a blind eye to his officers' alleged abuses because "they want to have a hero in the police".

With Mchunu sent packing, South Africa will have a new acting police minister from next month - Firoz Cachalia, a law professor who comes from a renowned family of anti-apartheid activists, and served as minister of Community Safety in Gauteng, South Africa's economic heartland, from 2004 to 2009.

In an interview with local TV station Newzroom Afrika, Cachalia said that Gen Mkhwanazi's decision to go public with his explosive allegations was "highly unusual", but if they turned out to be true then "we will be able to see in retrospect that he was perfectly justified in doing what he did".

So Gen Mkhwanazi's credibility is on the line - either he proves his allegations against Mchunu or he could fall on his sword.

But for now he has cemented his reputation as a brave police officer who took on his political bosses - twice.