Advocates’ hopes of legalising magic-mushroom therapy for mental illness have received a significant boost after a wealthy couple agreed to throw their substantial resources behind the campaign.

Investment banker Peter Hunt and his wife Tania de Jong have already tipped in at least $120,000 to half-fund Australia’s first trial on the therapy - being run at St Vincent’s Hospital - and set up a new charity.

Philanthropists Tania de Jong and Peter Hunt at their office in Melbourne, on Tuesday 29 January. Credit:Luis Enrique Ascui

“We’ve mentally got ourselves around the fact we’ll need to invest at least a million dollars in this,” Mr Hunt says.

The well-heeled couple are not the hippies you might expect extolling the virtues of psychedelic drugs, so how did Ms de Jong, a teetotalling opera singer, and Mr Hunt, who co-founded corporate advisory group Caliburn before selling it for $200 million-plus in 2011, get on board?