8:51 AM PT -- 9/2 -- O'Leary is denying any involvement in the alleged scam.
KO, through his attorney Andrew Brettler, tells TMZ ... "It appears that someone has been using my name and likeness without my knowledge, permission, or consent. I've never heard of any of these purported companies and have never conducted business with any of the plaintiffs who filed this suit."
He adds ... "Obviously, I want to get to the bottom of it too, as my rights have been violated. We will make sure that the bad actors are held accountable."
Kevin O'Leary and Kevin Harrington allegedly scammed tons of entrepreneurs out of hundreds of thousands of dollars ... according to claims in a new lawsuit.
The "Shark Tank" stars are being sued by 20 people who claim O'Leary and Harrington each played roles in what they say was a brazen scam to defraud hard-working entrepreneurs.
According to the lawsuit, obtained by TMZ, O'Leary and Harrington steered investors and entrepreneurs to hire one of two companies, InventureX or Ideazon, to handle crowdfunding for their startups.
In the suit, the folks who claim they got scammed say they were promised help raising funds for the businesses and some say the prospect of appearing on "Shark Tank" was dangled in front of them ... but they say once they paid money to the companies endorsed by "Shark Tank" stars, they got little to nothing in return, aside from a bill.
What's more, the suit claims the crowdfunding companies O'Leary allegedly endorsed might not even exist at all and suspect it may be a big "predatory fraud scheme.”
While 20 people are suing O'Leary and Harrington, those folks claim they are just one small faction of hundreds, if not thousands, of folks who fell victim to the scam.
We reached out to reps for "Shark Tank" ... so far, no word back.