Donald Trump has found himself in hot water over his now defunct for-profit investment school.

On Wednesday, a New York judge ruled that the self-proclaimed billionaire is personally liable for operating the school without the required license in a lawsuit filed by the state Attorney General.

"It is undisputed that Mr. Trump never complied with the licensing requirements," wrote NY Supreme Court Justice Cynthia S. Kern in a decision about the famous realtor's Trump University, according to Reuters.

In response, Trump's attorney Jeffrey Goldman called the ruling a mistake.

The decision came in an ongoing lawsuit filed last year by New York Attorney General Eric Schneiderman which accuses Trump of ripping off over 5,000 student who paid up to $35,000 to learn about his real estate investment techniques. Instead, the AG claims that the students were misled into taking expensive and useless seminars.

Damien LaVera, a spokesman for Schneiderman, called the judge's decision "an important victory." He added that the office looks forward to proving that Trump and the school defrauded students at an upcoming trial.

However, the judge did toss out some of the claims in the suit, and ruled that some pieces of evidence surpassed the statute of limitations.

Nevertheless, Trump remained confident that he is going to beat the $40 million fraud lawsuit and stated that he is considering re-opening the school, which ceased operation in late 2010.

"As soon as this case is over, we will consider re-opening the school to all our students and hire back the teachers and others, thereby creating lots of jobs for New York," Trump said in a statement, reports the New York Daily News.

Trump also accused the AG of using taxpayer dollars "to build his name and reputation by going after me and now his entire case has been totally decimated."

He added that the AG "is desperately trying to change his weak and ineffective image with the voters prior to election."

"This all for a school that has a 98% approval rating from its students ... In my opinion, he is a corrupt politician," said Trump.