A judge in South Africa will allow former Grand Slam doubles tennis champion Bob Hewitt to appeal his six-year jail sentence after he was convicted of rape and sexual assault, extending his bail pending a higher court's decision.

Judge Bert Bam ruled on Friday that he would not, however, allow 75-year-old Hewitt to appeal his guilty conviction. He added that another court may hand Hewitt a different sentence based on his age, poor health and the fact that the assaults happened in the 1980s and 1990s.

According to the judge's instruction, Hewitt will be confined to his farm in South Africa's Eastern Cape province during proceedings around his appeal hearing.

Australian-born Hewitt has denied all the charges.