Abuse of public office charges have been dropped against a former Renewal SA chief executive.

A long-running case against former Renewal SA boss John Hanlon has been dropped on the day his jury trial was due to start, after a District Court judge threw out key evidence against him.

The 64-year-old was charged with abuse of public office in 2020 after an investigation by then-Independent Commissioner Against Corruption (ICAC) Bruce Lander KC, in which it was alleged that Mr Hanlon billed taxpayers for a trip to Berlin in 2017 in which he did no official work for Renewal SA.

Mr Hanlon maintains his innocence.

Judge Tim Heffernan earlier this week excluded six statements made by German citizens from being presented at trial because they were obtained illegally without the permission of the German government.

David Edwardson KC, acting for Mr Hanlon, told the court his client would not have had an opportunity to challenge or test the German evidence.

“We're not talking about one witness - we’re talking about the whole of the German component,” he told the court.

“The Crown would be able to rely on the accumulative effect of the six statements as a means by which they could advance their proposition and to make good the case against the accused - that my client did not perform any work at all involved in Renewal SA or if he did, it was a token gesture, when the real purpose of his journey was to see his daughter give birth.

“They're trying to get in this evidence in the back door when they can't get it in the front door - it's quite extraordinary.”

It is the second time prosecutors have withdrawn their case against Mr Hanlon, after dropping them due to insufficient evidence in June 2021. 

Fresh charges were launched three months later, and it is those that have now been dropped. 

Mr Hanlon says the accusations have taken a serious emotional toll. 

“When you're fighting very senior people in politics and when you're fighting very, very senior people in the DPP, you need to have a strong legal team, you need to have a strong support system behind you,” he said.

“I have had that with family.”

SA Best MLC Frank Pangallo has called for a royal commission into the operations of the ICAC.

“ICAC and the Office of the Director of Public Prosecutions - two institutions that we should have confidence in - have failed again in this landmark case,” he said.

He called on Independent Commissioner Against Corruption Ann Vanstone KC and her head of investigations, Andrew Baker - who obtained the German statements against the advice of the Australian consulate-general in Berlin - to resign.