Young was meant to testify in July last year but failed to attend.
His attorneys sent two letters to the commission explaining why their client could not be present.
The main reason for Young not being at the commission was that he had recently had an eye operation and was battling to read.
According to his attorneys at the time, the commission’s schedule was also an issue.
Three days had been set aside for his evidence. However, Young said he would need a week or two, without cross-examination, to give his evidence-in-chief.
Young has reportedly raised concerns that the commission was not allowing allegations of fraud and corruption to be put to State witnesses as these were only meant to be dealt with in phase two of the hearing.
He has also accused the commission of being one-sided, in that it made no attempt to rigorously examine the evidence of government witnesses.
The commission’s work is divided into phases — the first consists of evidence mainly given by government officials and the second consists mainly of arms deal critics.
The commission, chaired by Judge Willie Seriti, was appointed by President Jacob Zuma three years ago to investigate alleged corruption in the country’s multi-billion-rand arms procurement deal in 1999.