Ted Cruz's private life has come under renewed scrutiny amid fresh allegations that his telephone number was listed in a "black book" of contacts kept by a Washington DC madam who provided prostitutes to politicians.
The claim adds a twist to recent allegations that the Republican presidential candidate - locked in a battle with Donald Trump for his party's nomination - cheated on his wife Heidi by having five mistresses.
Mr Cruz, who had previously dismissed those suggestions as "complete garbage and lies" spread by Mr Trump's supporters, denied categorically having extramarital affairs on Monday.
In a town hall interview with Fox News's Megyn Kelly, he declared: "I have always been faithful to my wife."
The initial allegations were published last month by the National Enquirer, a supermarket magazine that Mr Cruz has depicted as being owned by a friend of Mr Trump and briefed by one of his aides, Roger Stone.
But as the candidate issued his latest denial, it emerged that the magazine was about to give the rumours fresh impetus by reporting in its next edition that Mr Cruz's number is believed to appear in the contacts list of Deborah Palfrey, who ran an escort agency in Washington offering prostitutes for $300 (pounds 210) an hour.
Palfrey hanged herself in 2008 before she could serve a 55-year jail sentence imposed after a court convicted her of charges that included racketeering and money laundering.
Montgomery Sibley, her former lawyer, has appealed to the supreme court for permission to publish the contents of the so-called "black book" - said to contain 15,000 pages of phone records.
Mr Sibley told the National Enquirer that "time is of the essence" in publishing because it has phone numbers containing information "relevant to voters before they cast their ballot".
A lower court has already barred him from releasing the numbers or naming names.