The historic launch of cryptocurrency-backed exchange traded funds has been delayed at the 11th hour, with a powerful but undisclosed third-party broker blocking the three investment products from beginning to trade on the Cboe Australia exchange.

Fund managers Cosmos Asset Management and ETF Securities had expected to end a frustrating five-month wait on Wednesday after the corporate regulator and national clearing house both gave their blessing to this much-anticipated new corner of the booming ETF market.