Under pressure to lift the veil of secrecy over who bankrolled his Canadian charity that's affiliated with the Clinton Foundation, Vancouver-based mining mogul Frank Giustra late Friday released the names of 21 of its largest donors, most with connections to the mining and oil-drilling industries.

The Clinton Giustra Enterprise Partnership (Canada) did not list the amounts of the various donations. It said it only disclosed the identities of those leading contributors who provided written authorization, while releasing a second legal opinion asserting that under Canadian law, the rest of its 1,100 contributors should be kept confidential unless they agree to be identified.

Those named include Giustra, a major Clinton Foundation benefactor who has forged a globetrotting philanthropic partnership with former President Bill Clinton, Giustra's estranged wife, Alison Lawton, and his family foundation.

The partnership's secrecy has triggered controversy because the contributors' money ultimately benefited the U.S.-based foundation that Clinton built into a global force to fight poverty and disease, posing possible undisclosed conflicts of interest for his wife, Hillary Clinton, during her tenure as secretary of state between 2009 and 2013.

Disclosures about these entanglements - and questions about whether some are being concealed - are now dogging Hillary Clinton as she seeks the Democratic presidential nomination.