EXCLUSIVE: What Bill Clinton's 'Energizer mistress' looks like today. Family friend seen for first time since revelation his foundation helped her firm

The society blonde whose company benefited from a controversial $2million pledge from Bill Clinton's charity emerged from hiding today.

Julie Tauber McMahon has spent the past week holed up inside her $3 million mansion amid rampant speculation that she is the woman dubbed the 'Energizer' by Secret Service agents because of her frequent trysts with the former president.

The wealthy divorcee, 56, finally stepped outside this morning for the first time, showing off her toned figure in a white t-shirt and blue tennis skirt.

McMahon, a neighbor and 'family friend' of the Clintons, stooped to pick up a handful of newspapers before enjoying a few moments of sunshine.

SCROLL DOWN FOR VIDEO 

'Energizer': Julie Tauber McMahon denies that she has had an affair with Bill Clinton but has been alleged to be the mistress given the 'Energizer' nickname by the ex-president's Secret Service detail

Work out: Julie Tauber McMahon is known to be keen on keep fit and appeared to be planning to play tennis when she was seen in upstate New York

Keeping up with the news: Julie Tauber McMahon picked up copies of the New York Post and New York Daily News

Backer: McMahon owns a substantial stake in a company which received funding through the Clinton Global Initiative, which is more usually involved in assisting non-profits 

The brief sojourn came as welcome relief for her pet dog, who had just long enough to stretch his legs before being ushered back inside the five-bedroom, Georgian-style residence in upscale Chappaqua, New York.

Mother-of-three McMahon has spent the past week dodging questions about how a home insulation business she part owns landed a massive donation through the Clinton Global Initiative.

The Initiative works as a non-profit 'matchmaker', lining up philanthropists and charitable investors with organizations fighting poverty and other global challenges.

But in a highly unusual move, in 2010 it helped secure a commitment of $2million for Energy Pioneer Solutions, a private, for-profit home insulation firm run by McMahon and other alleged Clinton allies.

Clinton is also said to have personally intervened with then Energy Secretary Stephen Chu, according to The Wall Street Journal, helping the firm land a further $812,000 government grant.

Julie Tauber McMahon pictured left and right in 1977. There is speculation that she is the woman dubbed the 'Energizer' by Secret Service agents because of her frequent trysts with the former president

The revelation was seized upon by Republicans who accused the former President of funneling money towards the business interests of a woman who has long been rumored to be his mistress.

McMahon was said to matches the description of a buxom Clinton paramour written about by author and former journalist Ronald Kessler in his 2014 book, 'The First Family Detail: Secret Service Agents Reveal the Hidden Lives of Presidents'.

Kessler revealed that the mystery lover made brazen visits to the Clinton residence when Hillary was away and was there so frequently that Bill's Secret Service detail assigned her a call-sign.

They called her the Energizer - a reference to the famous toy bunny that 'keeps going and going and going' in the Energizer battery commercials - and agents were under orders not to stop, approach or question her, Kessler wrote.

Kessler did not name her and has not done so subsequently, but RadarOnline made the link to McMahon. 

Family: McMahon is divorced from her husband John, a former Goldman Sachs banker, and has three children, including her grown-up daughter Maddie

Society figure: The daughter of a millionaire Democratic donor, McMahon has been seen frequently at events in New York. She lives outside it in Chappaqua - the same town as the Clintons

No defense: Hillary Clinton claimed that speaking up for her husband's 'honor' would drag her into a fight at Donald Trump's 'level'

No defense: The Democratic frontrunner declined an opportunity to defend her husband's 'honor' because she claimed she was campaigning on 'issues' 

McMahon, whose father Joel Tauber was a multi-millionaire backer of the Democratic party, has denied the affair and last week described herself merely as a Clinton 'family friend.'

Her ex-husband John McMahon, a 59-year-old managing director of Goldman Sachs, also declined to speak with a reporter who called at his $5 million home in Greenwich, Connecticut. 

The former couple, who have three children, Andrew, Gwen and Madeline, are believed to have split up several years before the alleged liaisons reportedly began in around 2001.

The other owners of Energy Pioneer Solutions, formed to insulate homes in rural America, include Democratic National Committee Treasurer Andrew Tobias and former Democratic congressional candidate Scott Kleeb.

Non-profits such as the Clinton Global Initiative are not permitted to act based on private interests but a spokesman defended the donation as 'common practice in the broader philanthropic space.'

That did not stop Donald Trump seizing on the story to mock Hillary Clinton this week after she revealed plans to put her husband in charge of revitalizing the American economy if she wins the White House.

On the trail: Bill Clinton has been out acting as a spokeswoman for his wife, including last week in New Jersey

Home: The Clintons' home in Chappaqua, where - investigative journalist and author Ronald Kessler reported - Bill would rendezvous with the 'Energizer' when his wife was away

'Crooked Hillary said her husband is going to be in charge of the economy. If so, he should run, not her,' Trump tweeted. 'Will he bring the 'energizer' to D.C.?'

Trump went further in a TV interview with Fox News Channel Wednesday in which he brought up an historic rape allegation leveled against the former President in 1999.

Juanita Broaddrick, now a 73-year-old grandmother, came forward that year to claim that Clinton had assaulted her in an Arkansas hotel room in 1978 - an accusation his lawyers said was 'categorically false'.

But when asked yesterday on CNN if she felt compelled to defend her husband's 'honor', Hillary replied: 'No, not at all.'

She added: 'I know that that's exactly what he [Trump] is fishing for. I'm not gonna be responding.'