Donald Trump's recently-hired convention manager, Paul Manafort, on Sunday suggested that GOP rival Ted Cruz was using "Gestapo tactics" to steal the nomination out from under the billionaire mogul.

Meet the Press host Chuck Todd noted during an interview with Manafort that Trump ally Roger Stone had threatened to reveal the hotel numbers of delegates who refused to vote for Trump at the Republican National Convention.

But Manafort insisted that Stone was "not an official part of the campaign."

According to the longtime GOP operative, Cruz had a campaigning "style" that included threatening delegates.

"You go to these county conventions and you see the Gestapo tactics, the scored Earth tactics," Manafort opined.

"Gestapo!" Todd exclaimed. "That's a strong word."

Manafort explained that the Trump campaign planned to file "several protests" against Cruz "because the reality is, they are not playing by the rules."

While he did not rule out the possibility of showering delegates with gifts to obtain their support, Manafort argued that the "best way" to win them over was with Trump's message.

"When we get into those final arguments, which is the end game of the end game, that persuasion starts to have an impact," he said.