Having resigned in March, the Briton has now all but confirmed rumors he was pushed out of formula one by its F1 chief executive Ecclestone.
Parr said the 82-year-old had made it clear to Williams' board that a favorable Concorde Agreement deal would not be forthcoming while he was at the helm.
Now, the 47-year-old has told Bloomberg journalist Alex Duff that the European Commission should look into how Ecclestone negotiated the new deals, including reportedly $45 million each for Red Bull and Ferrari and seats on the F1 board.
"There's a strong case that an unequal division of power and money to a subset of teams is unlawful," Parr said.
Although refusing to say if he wanted Williams to make a complaint, he suggested other F1 teams accept the situation because they are "highly dependent" on Ecclestone's "goodwill".