Since Dutton became opposition leader, the billionaire mining magnate has cultivated their bond. We look back at their increasingly close relationship

• Listen to a teaser of our new narrative podcast series Gina

The buzz from Gina Rinehart’s 70th birthday party was reportedly “so spectacular” that it drifted across the Swan River from the mining magnate’s Perth home, catching the attention of people more than a kilometre away.

Four hundred guests, mostly employees, had gathered to mark the milestone of the Hancock Prospecting head, who is deferentially referred to as “the Chairman” or “Mrs Rinehart”.