Former Orica chief Malcolm Broomhead is Australia's most connected corporate director.

In exclusive data compiled for The Power Index by ASX data specialists Optimice to round off our extensive 13-part investigation into boardroom power, Broomhead, who serves on the board of global miner BHP Billiton and chairs the country's second-largest listed rail firm Asciano, boasts over $1.72 trillion in capital within one degree of separation.