One of the biggest alleged corruption sagas in corporate Australia has led to the charging of a second former high-profile chief executive, one-time boss of engineering giant UGL, Russell Waugh.

Mr Waugh has been charged in relation to a $15 million offshore payment made while he was a senior executive at construction giant Leighton Holdings. He joins Peter Gregg - who was Leighton's finance chief at the time - in facing serious criminal charges connected to the 2011 payment.

Former Primary Health Care chief executive Peter Gregg denies working with major shareholder, Jangho Group. Credit:Daniel Munoz

Last year, as part of an expose highlighting alleged global corruption at Unaoil, Fairfax Media revealed the existence of the $15 million Leighton payment and the fact it was received by an allegedly crooked Dubai consultant.

Fairfax Media's previous investigation into Mr Waugh's role as managing director of Leighton's overseas operation led to his sacking by new employer UGL in 2013, despite Mr Waugh's strident denials of wrongdoing.