Forensic auditor Johan van der Walt will spend his fifth day in the witness box on Wednesday, in the third week of the Schabir Shaik fraud and corruption trial in the Durban High Court.

Van der Walt who was commissioned by the Scorpions and given access to a strongroom of documents has just passed the halfway mark in his 259 page audit report.

The report is accompanied by a 20-page addendum and 22 lever-arch files crammed with annexures and supporting documents neatly spread around the front of the courtroom.

On Wednesday, Scorpions spokesman Sipho Ngwema said no other investigations relating to the case were happening outside the trial because the State commenced with its case when it had everything it needed.

"We are concentrating on the case and all our efforts are limited to the case," said Ngwema.

He said they were hoping to be finished by December as the defence "admitted to a number of issues" thereby reducing the number of witnesses the State needed to call by half.

Originally the State released a list of 100 witnesses but said not everyone had been included on the list.

So far five of them, including Van der Walt, have already given testimony.

Scorpions investigators were currently concentrating their efforts on providing the State's legal team with "whatever is needed" in the courtroom, said Ngwema.

He said Van der Walt was likely to be in the witness box for at least another two to three weeks and the witnesses that followed would be called to support the forensic evidence given.

Van der Walt is giving evidence on the paper trail which links Shaik with Deputy President Jacob Zuma.

Shaik faces two charges of corruption and one of fraud relating to payments of R500 000 per year to Deputy President Jacob Zuma for protection against investigations into arms deal irregularities.

He has pleaded not guilty.

With acknowledgement to Sapa.