Melania Trump's direct response when asked if she was with Donald Trump for his money

Melania Trump has been swatting away questions about the nature of her relationship with Donald Trump since way back in 1999.

From his time as the 'You're Fired!' merchant on the US Apprentice all the way up to his second term as 'leader of the free world', Donald Trump has always been a polarising figure.

In fact, the one time he probably had everyone backing him for victory was during WWE's Battle of Billionaires, when he shaved Vince McMahon cue ball bald.

Yet, there has been one person who has resolutely stood by his side after every controversy and scandal in recent years, his wife, Melania Trump.

Age-gap relationships are always a hot topic, just ask Olivia Wilde, and marriage between the President and the First Lady is one of them.

Trump recently celebrated his 80th birthday during the UFC Freedom 250 event, where which he joked about his own demise in a terrorist attack with Joe Rogan.

Melania, meanwhile, is 56, with the pair first meeting when she was 28.

The gap led to some questioning if the Slovenian was only with Trump for his money, but Melania has always given the suggestion short shrift.

Donald and Melania Trump at UFC Freedom 250 (Photo by Evan Vucci - Pool/Getty Images)

Melania Trump denied she was with Donald Trump for money in 1999

Melania first met Trump in 1998 and after the couple went public the following year, she was dogged with questions about the nature of their relationship.

During an interview on ABC News, as reported by Hello, way back in 1999, Melania rubbished claims she was with Trump for his vast fortune.

"You know, the people, they don't know me," she said. "People who talk like this, they don't know me."

Reporter Dan Dahler fired back: "Well, you don't see many 26-year-old supermodels on the arm of a 53-year-old car mechanic."

But again, Melania remained steadfast in her stance, replying: "You know what, you can't sleep or to hug or to talk with beautiful things, with beautiful apartment, beautiful plane, beautiful cars, beautiful houses, you can't do that.

"You could feel very empty," she added. "And if somebody said, 'You're with the man because he's rich and famous,' they don't know me."

Melania, who went on to become the first-ever First Lady to be born outside the United States, married Trump in 2005 following Trump's proposal in 2004.

They had a son together, Barron Trump, in 2006, who became Trump's fifth child, following Donald Jr., Ivanka, Eric and Tiffany from his two previous marriages.