The DCCC Tuesday confirmed to The Hill it received a letter from Adelson’s attorney.

“We just received and are reviewing Mr. Adelson’s attorney’s letter,” DCCC spokesman Jesse Ferguson said in an email. Ferguson did not respond to a follow-up inquiry.

In late June, the DCCC sent out a release alleging that prostitution money tied to Adelson helped fund the campaigns of Reps. Sean DuffySean DuffyOvernight Finance: GOP offers measure to repeal arbitration rule | Feds fine Exxon M for Russian sanctions violations | Senate panel sticks with 2017 funding levels for budget | Trump tax nominee advances | Trump unveils first reg agenda Realtors endorse House flood insurance extension The Hill's 12:30 Report MORE (R-Wis.) and Jim Renacci (R-Ohio), as well as other GOP incumbents.

The charge stems from a lawsuit filed by a former employee of Adelson’s, who claimed that he personally approved of prostitution at one of his properties. Adelson denies the charges, and Politifact rated the claim as “Pants on Fire.”

“Immediately retract and apologize for defamatory statements falsely accusing Mr. Adelson of encouraging and profiting from prostitution, maliciously branding Mr. Adelson as a pimp who has given ‘Chinese prostitution money’ to your political opponents,” the letter from Adelson's attorney, first obtained by the Las Vegas Sun, reads in part. “These false allegations constitute libel per se entitling Mr. Adelson to compensatory and punitive damages.”

Adelson was a major donor to the campaign of former House Speaker Newt Gingrich during the Republican primaries, and recently switched his support to presumptive GOP nominee Mitt Romney, donating to his campaign, as well as non-profits and super-PACs backing his candidacy.

Adelson and his wife recently donated $10 million to Restore Our Future, a pro-Romney super-PAC, and reports say Adelson has pledged up to $100 million to aid Republican causes in the 2012 election.