Ted Cruz has finally denied cheating on his wife - at the same time as his phone number is alleged to be in the 'Black Book' used by the notorious DC Madam.

The Republican presidential candidate's digits are reportedly be included in 15,000 pages of phone records dating back two decades.

The allegations come after Cruz was accused of cheating on his wife Heidi and having had five 'mistresses'.

He has called the claims 'complete garbage' but declined to say that he had never cheated on his wife, until on Monday the told Fox News: 'I have always been faithful to my wife.'

However Cruz married Heidi in 2001 and some of the numbers in the DC Madam's Black Book date back to the mid 1990s when he was working his way up in politics.

Cruz has made his evangelical faith a central plank of his campaign and contrasted his family values to those of Donald Trump, who is leading the polls among Republicans.

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Cruz, here with Megyn Kelly at a town hall campaign event in Madison, Wisconsin, told her he has always been faithful to his wife

Stand by your man: Heidi Cruz went on stage with him at the end of the town hall, where he was accompanied by two failed presidential candidates now endorsing him - Scott Walker (far left) and Carly Fiorina (far right)

Ted Cruz's phone number is said to have been found in the 'Black Book' used by the notorious DC Madam Deborah Jeane Palfrey (right). She is now dead.

Endorser: Ted Cruz was joined for the town hall by Scott Walker, the Wisconsin governor who has become a supporter of his efforts to gain the Republican nomination

Family values: Ted Cruz has taken his wife Heidi and their two daughters, Catherine and Caroline, on the stump

Trump has been married three times and cheated on his first wife Ivana while they were still married.

The DC Madam, Deborah Jeane Palfrey, operated Pamela Martin and Associates and made $2 million servicing wealthy clients over more than a decade.

At the time of her arrest in 2006 her escorts had slept with officials in the White House, the Pentagon, lobbyists and high-powered lawyers.

Palfrey hanged herself in May 2008 before she could be sent to prison to serve a 55 year sentence.

Her Black Book has been circulating on the Internet for years but now RadarOnline claims that Cruz's number was among those listed.

The book contains numbers dating from 1995 to 2006 and it is not clear when Cruz is said to have been featured.

Cruz, 45, is originally from Houston, Texas and moved to Washington in the mid 1990s to clerk for two Supreme Court Justices.

He went on to work for a Washington law firm and then was an adviser to George W Bush's 2000 election campaign.

Cruz married Heidi in 2001. Some of the numbers in the DC Madam's Black Book date back to the mid 1990s when he was working his way up in Republican politics

Together: Cruz hugs his wife Heidi as they arrive at a campaign stop at Waukesha County Exposition Center yesterday

Cruz feeds his wife some ice cream during a campaign stop at the Glorioso's Italian Market in Milwaukee yesterday

Between 2003 and 2008 Cruz served as the Solicitor General of Texas before sweeping into the Senate on the Tea Party wave in 2012.

The Black Book has resurfaced because of Montgomery Blair Sibley, a former lawyer for Palfrey, who is trying to lift a gag order preventing him from releasing the phone records, over which he has custody.

He wants to make them public because he says their contents will have a bearing on the Presidential election because they have a candidate's number in them.

RadarOnline reported that the mystery man 'has to be Cruz'.

While Cruz told Fox that he has never cheated on his wife, he was not able to give such a clear answer when asked by Daily Mail Online a week ago.

Asked directly to 'tell us on the record that you've never been unfaithful to your wife?' Cruz dodged the question and attacked Trump.

Cruz said the story was 'total lies' and was 'planted by Donald Trump's henchmen'. Carly Fiorina, the failed presidential candidate who is endorsing also intervened to answer.

Cruz told Fox that he has never cheated on his wife, but he was not able to give such a clear answer when asked by Daily Mail Online a week ago

The show must go on: Cruz speaks at a campaign stop at Waukesha County Exposition Center

The claims about him cheating with five women started a witch hunt and a backlash which suggested that Trump was behind the story.

In a bizarre scene, Amanda Carpenter, a female CNN contributor had to deny she had slept with Cruz - live on air.

Carpenter said it was 'tabloid trash' and that Trump's campaign should be 'ashamed for spreading this kind of smut'.

Rumors have been circulating on the Internet for week with #crusexscandal circulating on Twitter before the Enquirer ran its two page story.

It alleged that Cruz had sex with a Republican political consultant for the party at one of the party's state events.

Another of the women was supposedly a Washington lawyer and a third was a woman who worked on one of his campaigns.

The fourth woman was said to be a schoolteacher in Austin, Texas, who had a fling with Cruz after he was appointed Texas Solicitor General in 2003.

Few details of the prostitute were revealed beyond her nightly fee.

Show of strength: Cruz gives his wife a kiss after the pair eat ice cream at the Glorioso's Italian Market

Cruz, pictured with Heidi and daughter Caroline, said the story of him being unfaithful to his wife was 'total lies'

Donald Trump's spokeswoman Katrina Pierson (left) pushed back on allegations - that started with a National Enquirer story - that she had an affair and 'came on' to Sen. Ted Cruz - and so did Amanda Carpenter (right)

In its story Enquirer ran a pixelated row of photos of the women which were quickly identified by blogs and websites.

Among them was Katrina Pierson who is currently a spokesman for the Trump's campaign.

She Tweeted: 'Of course the National Enquirer story is 100% FALSE!!! I only speak to myself, however.'.

The story ran after Cruz and Trump were already engaged in open warfare; the Texan called the real estate mogul a 'snivelling coward' for launching bitter personal attacks on his wife.

In an angry speech Cruz told the real estate mogul to 'leave Heidi the hell alone'.

Cruz was responding to a Twitter post by Trump which showed an unflattering picture of Mrs Cruz next to a glamorous shot of his wife Melania.