The Delaware Court of Chancery on Wednesday ordered UnitedHealth Group Inc. to turn over to stockholders a wide range of corporate documents, including information referenced in a whistleblower suit outlining a supposed scheme to overbill Medicare by possibly “billions of dollars.”

The ruling from Vice Chancellor Tamika Montgomery-Reeves granted Amalgamated Bank and two pension funds most of the document demands they sought in conjunction with an investor probe into Medicare payments made over a 12-year period.