Mellon donation
(Photo : Emily Elconin/Getty Images for DNC)
Democrats put up billboards in Michigan in February linking Timothy Mellon's donations to Robert F. Kennedy Jr.'s presidential campaign to Donald Trump's. Mellon contributed $50 million to the Make America Great Again super PAC a day after the former president was convicted in Manhattan criminal court in May.

A secretive billionaire who backed Robert F. Kennedy Jr.'s presidential campaign donated $50 million to a super PAC supporting Donald Trump the day after the former president was convicted in May of 34 felony counts in his New York hush money trial, according to a report. 

The huge donation from Timothy Mellon, an heir to the wealthy and influential Mellon family from Pittsburgh, Pa., came as the PAC, Make America Great Again Inc., had only $34.5 million on hand at the end of April, the New York Times reported. 

Mellon's contribution made up the lion's share of the $70 million the super PAC raised in May, the report said. 

The super PAC on Wednesday and Thursday began reserving $30 million in ads to run in the swing states of Georgia and Pennsylvania over the Fourth of July holiday. 

The report said Mellon, the grandson of former Treasury Secretary Andrew Mellon, is the first donor to give $100 million in disclosed federal contributions this year.

He contributed $25 million each to super PACs supporting Kennedy's campaign and Trump's campaign.

Mellon did not respond to requests for comment from the New York Times.