Hubert, the former Rovers vice-chairman, told the Lancashire Evening Telegraph: "I've got Rovers' interests at heart and I wouldn't have recommended Daniel to the powers-that-be if I didn't think he was suitable.
"This is not a Wall Street predator, for want of a better word, he's a genuine lad who wants the best for Blackburn Rovers."
Hubert had a hand in bringing Williams and Rovers together when the search for new investors gathered pace earlier this year, and having spent time in his company during the intervening months, he is convinced the US-based entrepreneur is a passionate Blackburn supporter whose main motivation is to see the club prosper, rather than make a quick return on any investment.
"I've been with Daniel to two or three games since this process began and make no mistake, he's passionate about this club," said Hubert.
"When he met Ronnie Clayton and Bryan Douglas, it was like a young girl meeting a famous film star.
"I loaned him several books on the Rovers when he first came over, and he's genuinely interested, and he is a supporter, there's no question about that.
"He's not here for the glory, and he's not here for the money because he's very, very mindful of the Jack Walker legacy."