Former NSW Premier and Optus senior executive Gladys Berejiklian has lost her bid to overturn findings of serious corrupt conduct.

Fees paid to the directors of Singtel – the owner of Optus – have soared by more than 80 per cent in just one year.

The directors of Optus owner Singtel were given major pay rises just weeks before the telco suffered one of the biggest data breaches in Australia’s history.