Ghosn, who had led the automaker for two decades before his arrest in November last year, has claimed his innocence.
The contents of the probe, led by Nissan's audit committee formed by members including external directors, will not likely be made public, given that they could influence the court proceedings of his cases.
Ghosn's defense counsel said earlier this week his first hearing could be held in March at the Tokyo District Court.
Nissan's in-house probe has led to Ghosn's arrest through a plea-bargain deal between the carmaker's senior officials and prosecutors.
According to the probe, Ghosn made Nissan purchase or refurbish luxurious homes and pay for his golf club membership, among other uses of company funds and assets for his private purposes, company officials said earlier.