Donald Trump. AP Photo/Alex Sanz Real-estate mogul Donald Trump's attacks against Sen. Ted Cruz (R-Texas) on Saturday apparently did not go over well at a South Carolina event.

Trump ended his 45-minute speech by taking shots at Cruz, his closest rival in the Republican presidential race.

Trump warned that candidates like Cruz would hire "political hacks" in their administrations.

"I mean, you give a campaign contribution to Ted Cruz, you get whatever the hell you want, OK? Whatever you want. And he's a very nice guy," he said at the South Carolina Tea Party Convention.

Some members of the audience then booed Trump, who laughed but proceeded to criticize Cruz for not reporting two bank loans that were used finance his 2012 Senate race.

"Excuse me. Excuse me. He didn't report his bank loans," Trump told the crowd, which continued to boo, reportedly loudly.

"He didn't report his bank loans," he reiterated. "Say whatever you want. He didn't report his bank loans. It's OK. He didn't report his bank loans. He's got bank loans from Goldman Sachs. He's got bank loans from Citibank folks. And then he acts like Robin Hood. Say whatever you want."

The bank-loan attack mirrors part of Trump's raging, eight-hour tweetstorm against Cruz earlier in the day. Among other things, Trump accused Cruz of "purposely" and "illegally" choosing to not report the loans to the federal government at the time. Cruz has dismissed the issue as a minor paperwork snafu.

Watch Trump get booed below: