Former New South Wales Premier Gladys Berejiklian has failed to overturn a finding of serious corrupt conduct against her.

The Independent Commission Against Corruption released its report last June after hearing evidence about a secret relationship between Ms Berejiklian and former Wagga Wagga M-P Daryl Maguire.

It didn't recommend criminal charges be pursued against Ms Berejiklian, BUT it made findings of serious corrupt conduct against the pair.

Today the NSW Court of Appeal rejected her appeal against the corruption finding.