In a shocking report tabled in parliament on Friday, the unit details progress in its investigations and the criminal charges it has brought against suspects.

The interim annual report, covering investigations in 2010 and 2011, reveals that more than R2-billion in tenders and irregular spending at provincial level is under investigation.

The unit is also investigating R700-million in questionable spending by national state departments.

The biggest culprits appear to be the Department of Rural Development and Land Reform, with Public Works and Human Settlements beset with maladministration and wasted millions.

About R500-million is thought to have vanished at the Department of Land Reform in the form of 36 fraudulent land grants.

"The money is supposed to be given to successful land claimants so they can redevelop their land," said Land Reform Department spokesman Mtobeli Mxotwa.

He said Minister of Land Reform Gugile Nkwinti last year asked President Jacob Zuma to authorise the investigation.

The report says the unit is expected to have a "long-term relationship" with the Department of Land Reform with investigations planned to continue until March 2014.

So far, the investigations into the department have led to four KwaZulu-Natal officials and a businessman being arrested. They are out on bail.

The unit's spokesman, Boy Ndala, would not identify the accused.

The report says that farms earmarked for emerging farmers were not transferred to the "intended beneficiaries but to external entities not linked to the grant processes".

Three farms, valued at R51-million, have been seized from people involved in questionable deals and are being returned to the department.

The Asset Forfeiture Unit has been asked to seize other farms that have been linked to fraudulent land grants worth about R90-million.

No one has been fired in the department because the investigations are continuing, said Mxotwa.

But 12 officials face disciplinary action, and three have been suspended.

Institute for Accountability director Paul Hoffman said the only way to stop endemic corruption was to "end the culture of impunity".

Hoffman said accountability and transparency in government were essential.

The director of the Centre for the Study of Democracy, Professor Steven Friedman, said corruption could be explained by the prevalence of gross inequality.

"If you have such inequality, people who can get hold of state resources to lever themselves upwards will do so.

"The only way many people can live a middle-class lifestyle is by getting hold of state resources."

The Department of Public Works - which made headlines when irregular police leases involving businessman Roux Shabangu and former national police commissioner Bheki Cele were investigated by the Public Protector - is also under the unit's spotlight: 41 leases are being investigated.

Problems include missing or non-existent lease agreements, rents far above market rates and lease deals signed before bid committee approval.

In one instance, 27 leases, totalling R325-million, were signed with one service provider and two officials allegedly received R4-million in kickbacks.

Public Works in KwaZulu-Natal is also under review. I nvestigations have unearthed "serious challenges in supply chain management" . Projects totalling R900-million are being reviewed.

Municipalities were revealed, in the unit' s report, as the worst offenders, with over R3-billion in spending under review.

Twenty-four municipalities in North West alone are being investigated .

The common threads in the investigations are tenders and contracts being awarded to municipal officials, irregular staff appointments, and wasteful spending.

At the Moses Kotane municipality in North West, a data capturer who scored the lowest marks in his interview was appointed. He was the son of the municipal manager.

In Tshwane, R1.9-billion in irregular spending is being investigated.

A report by Public Service and Administration Minister Lindiwe Sisulu showed last week that only two of 998 department officials convicted of maladministration in 2009 and 2010 are in prison.