Creevey's company Moment Media owns 50.1 per cent of Helipad, while 49.9 per cent is held by Diamond's Chardonnay Investments - which owns the intellectual property rights to Hutchence's work.
The pair set up Helipad in the tax haven of Mauritius in 2015.
Emails written by Diamond's lawyer and a staff member of the offshore law firm Appleby also refers to Diamond as the "beneficial owner of Michael Hutchence's estate".
Diamond was made an executor of Hutchence's will but quit amid disputes between the singer's family and his partner Paula Yates.
Hutchence's mother Patricia Glassop and his sister Tina Hutchence took Diamond to court in the late 1990s after discovering that while the singer had earned millions with INXS, there was virtually no money left by the time he died and many of the assets they believed he owned weren't in fact held in his name.
They claimed Diamond and fellow executor Andrew Paul hid the rocker's assets in a complex web of offshore trusts to save tax.
The year before his death, the 37-year-old star made a will which granted Amnesty International and Greenpeace A$250,000 each.
His only child, Heavenly Hiraani Tiger Lily was to receive the remaining half of his estate, with the rest split between Yates, his mother, father, brother and sister.
British tabloid the Sun reported in July that Tiger Lily stood to inherit "millions" from her dad's song royalties when she turned 21 this year, thanks to a trust fund set up by Hutchence.
- AAP