The former Director General of the Anti-Corruption Commission (ACC), Paulus Noa, says the commission's success should not be measured solely by cases that reach the criminal courts.
Speaking on NBC's 1 on 1 programme, Noa, who led the commission for two decades, said its performance should also be assessed through investigations and administrative action.
He said allegations must have reasonable grounds before the commission prioritises them.
"The law provides that if you find that a particular complain is such a vexatious complain – meaning that what is being complained about has no value – you cannot give it priority in place of a priority case. Maybe there is so much public interest or the value involved or the nature of the complain that is being alleged, but there must be reasonable grounds for a decision to be made."
Noa said limited resources have challenged the commission, despite its work on major cases such as Fishrot and the NamCor saga.
He also pointed to corruption allegations at the Ministry of Health and Social Services (MoHSS), some raised by former Health Minister Bernhard Haufiku, saying the lack of preliminary investigations makes them harder to pursue.
"Some of the allegations have elements of administrative irregularities, while at the same time there are elements of criminal corruption in them. The challenge with the Ministry of Health is that whatever they are reporting to ACC from their side, they have not done anything."
Meanwhile, the ACC has summoned the Namibia Airports Company (NAC) chief executive officer as part of an investigation into alleged corruption at the state-owned company.
The inquiry includes several transactions and appointments, a tender for renovations to the Aircraft Rescue and Fire Fighting facility at Hosea Kutako International Airport, and the disposal of 19 NAC vehicles.
NAC has temporarily suspended all new and active procurement activities.
"Oh yes, we have served summons to the CEO, and obviously, a CEO is an accounting officer of an institution. An institution is being alleged to be involved in corruption. Now, for us to understand whether it's true that there was corruption, we need to have access to the documentation and the decisions that were taken for whatever is alleged to have happened. As I am speaking to you now, I will not say if it was provided. I will not be able to say yes or no."
Noa said the Prevention of Organised Crime Act (POCA) and Unexplained Wealth Orders could complement the ACC's work in cases where evidence is insufficient for prosecution.
Meanwhile, Transparency International's latest figures give Namibia a score of 46 out of 100, down three points from last year, placing the country 65th out of 182 countries.