After calling Judge Gonzalo Curiel a “hater of Donald Trump” and a “total disgrace” last week at his San Diego rally, the presumptive Republican presidential nominee hit the judge again Thursday, saying Curiel, who is presiding over the Trump University fraud case, was in “absolute conflict” owing to his “Mexican heritage.”

In an interview with the Wall Street Journal, Trump insisted that the U. S. district judge’s background was important, considering Trump’s campaign speaks against illegal immigration and building a wall along the U. S.–Mexico border.

“I’m building a wall. It’s an inherent conflict of interest,” Trump said. Curiel was born in Indiana to parents who hail from Mexico.

In the interview, Trump also pointed out that the judge was a former colleague of one of the Trump University plaintiff's lawyers, Jason Forge.

“Neither Judge Curiel’s ethnicity nor the fact that we crossed paths as prosecutors in the U.S. Attorney’s Office well over a decade ago is to blame” for Trump’s words or actions, Forge told the Journal.

Earlier, at his San Diego rally Monday, Trump spent 12 minutes of his 58-minute speech on the Trump University issue. He argued that the judge should be removed from the case.

“I think Judge Curiel should be ashamed of himself,” he said, “I’m telling you, this court system, judges in this court system, federal court, they ought to look into Judge Curiel. Because what Judge Curiel is doing is a total disgrace, OK? But we’ll come back in November. Wouldn’t that be wild if I’m president and I come back to do a civil case? Where everybody likes it. OK. This is called life, folks.”

He also tweeted later saying, "I have a judge in the Trump University civil case, Gonzalo Curiel (San Diego), who is very unfair. An Obama pick. Totally biased-hates Trump."

Trump is currently facing three class action lawsuits against Trump University. The New York real estate mogul, who has been accused of fraud, denies any wrongdoing and has declared to fight the allegations in court.