Mr Hersch has been chief financial officer of a high-net-wealth family investment office since 2010.
"The Disbursement Funding Business is complementary but separate from Macquarie Medico Legal (MML), a business that JustKapital acquired in January 2016 for circa $19 million," said a statement by JustKapital.
"MML is an established and growing business that provides law firms with independent medical, psychological and radiology reports for victims of negligence by third parties."
Ms Diane Jones has also been appointed as JustKapital's chief operations officer and chief financial officer.