A woman who claims she was raped over 40 years ago is allowed to have the matter brought to trial, the Constitutional Court ruled on Thursday.

The court ruled that the High Court in Kimberly was wrong to give the man she accused a permanent stay of prosecution.

Reading the judgment, Judge Albie Sachs said the man's right to a fair trial would be protected by a presumption of innocence.

"Accordingly she should not be stopped from giving her account to enable the High Court to decide."

The woman said she was raped when she was 13 by a wealthy family friend.

She alleges that he drove her to his farm and forced her to have sex.

The Director of Public Prosecutions had declined to prosecute when the woman tried to lay a charge in her 50s.

She then tried a civil trial but the man successfully applied for a permanent stay of prosecution.

The Constitutional Court heard that the man might not be able to provide witnesses or documentation to prove his innocence and his accuser might not be able to recall events reliably after so long.

The judges set aside the permanent stay of prosecution and said the woman should be allowed to have a trial for the truth to be determined.