Photo

Senator Ted Cruz is under fire from Senator Marco Rubio’s campaign, which accuses him and his campaign of employing more “dirty tricks” ahead of the Republican caucuses in Hawaii on Tuesday and spreading false rumors that Mr. Rubio is dropping out of the race.

Emails that appeared to have come from the Cruz campaign were sent to his supporters in Hawaii promoting a CNN report saying some of Mr. Rubio’s advisers see no path for him to win the Republican presidential nomination, and suggesting that he might leave the race before the March 15 primary in Florida. A spokesman for Mr. Rubio said that report is false.

“Senator Cruz is up to his dirty tricks again spreading false rumors and lies,” said Joe Pounder, a spokesman for Mr. Rubio.

In February, Mr. Cruz was forced to apologize to Ben Carson, who dropped out of the Republican race last week, after his campaign told caucusgoers in Iowa on the day of the voting that Mr. Carson was planning to quit the race. The Cruz campaign said at the time that it was just relaying information from news reports, but later it acknowledged that it was wrong to spread bad information.

Both Mr. Carson and Donald J. Trump, the Republican front-runner, used the episode to brand Mr. Cruz as an unscrupulous politician who cost Mr. Carson votes in Iowa.

The email that was said to have been sent from the Cruz campaign, which was forwarded by Mr. Rubio’s campaign, quotes Hawaii caucus voters as saying that they did not want to waste a vote on Mr. Rubio because he was likely to drop out.

There are 19 delegates at stake in Hawaii on Tuesday.

But the Cruz campaign said it had nothing to do with the email, asserting that volunteers in Hawaii sent it without permission. The volunteers have been instructed by the campaign’s lawyers to stop using its logo and remove any similar posts from social media accounts.

“The at-issue email and social media posting was not sanctioned by the Cruz for President campaign,” said Alice Stewart, a spokeswoman for Mr. Cruz. “The campaign became aware of the email this morning by press accounts, and upon investigation learned that some volunteers in Hawaii were involved in the posting.”