But Ncongwane says the project, set up to help landless, black farmers, became fraudulent and is now being scrutinised by prosecutors, who claim that R200m in public money that was pumped into the project was siphoned off.
They say they are building a case, after dropping charges last year against three provincial officials and five business associates due to lack of evidence.
All those implicated deny any wrongdoing.
Since Ramaphosa took over as president from Jacob Zuma early last year, no senior government official has been convicted of financial wrongdoing, despite a special investigations unit having been set up to deal with claims of corruption.
"We see corruption being investigated, but no one is being arrested. If it was me, I would have long been in jail, that's the painful part." Ncongwane said.
Opposition leaders have used this to their advantage, centring their campaigns on corruption.
Opinion polls say the ANC is still backed by a majority of voters, but its support continues to slide.
Some political analysts say it could slip further ahead of the May 8 vote.