Master Leslie, a High Court official, ruled disclosure of a report into councillor and former Lib Dem MP Mike Hancock was necessary so that the woman could feel she had "a fair hearing and a fair crack of the whip".
The report was written by Nigel Pascoe QC, who was asked by the city council to investigate the allegations for code of conduct proceedings.
The woman, a female constituent and a young mother, says Mr Hancock made "unwelcome sexual approaches". The leaked, redacted version of the report describes the account she gave as "credible".
More top news
It came as the US President said he would stop migrant family separations on America’s borders.
A report found that more than 450 patients at the Gosport War Memorial Hospital had their lives shortened.
The expected revolt by pro-EU Tories crumbled as heavily pregnant and sick opposition MPs turned out to support a ‘meaningful vote’.