A former investor behind Sydney FC and the Central Coast Mariners helped initiate the discussions that led to the complicated, convoluted proposal from a London-based blockchain-trading firm to take control of A-League premiers Perth Glory.

Real estate mogul Peter Turnbull, one of the Sky Blues' founding fathers who later served as a director with the Mariners, introduced Glory chairman Tony Sage to the London Football Exchange (LFE), which is poised to buy a majority share in the club pending approval from Football Federation Australia.

The LFE is promising to make Perth the first in a City Football Group-style suite of approximately seven clubs from around the world and use cryptocurrency to create an "ecosystem" that will enable fans to connect on a "more intimate basis" with their teams.

However, key figures at FFA, other clubs and around the game hold serious doubts over the legitimacy of their operation, sources say.