Fashion designer reveals alleged real reason behind infamous elevator fight between Jay-Z and Solange Knowles

The potential real cause of the infamous elevator fight involving Beyoncé's husband, rap mogul Jay-Z, and her younger sister Solange Knowles has been detailed by a fashion designer who claims to have been at the heart of the drama.

Security footage of the incident spread around the world, showing Solange furiously attacking Jay-Z in an elevator during the 2014 Met Gala, while Beyoncé passively watches the beatdown.

This incident dominated global headlines, with theories flying around about the cause of this rupture at the center of one of music's greatest power couples.

Many believed the source of Solange's rage was the Empire State of Mind rapper's alleged affair Rachel Roy, a fashion designer who started her career at Rocawear - a clothing label partly owned by Jay-Z.

But another designer has revealed a new dimension to the 2014 elevator fight story, with one comment from Beyoncé's husband at the Met Gala allegedly sending Solange into a frenzy.

11 years after the incident shocked the couple's fans around the world, fashion designer Oscar G Lopez has spilled the beans on what motivated Solange's anger - and it might be down to a dress he made for the red carpet.

Lopez gained national fame and Roy's attention after winning the first season of Project Runway spinoff Under the Gunn. With just two weeks to work, the Cuban designer turned reams of sequined lace and silk organza into a stuning Met Gala gown.

Roy, then 40, had gone to the high fashion event wearing Lopez's finished designs, a gorgeous black lace gown with a structured corset.

There, Roy saw her former Rocawear employer, who attended the event in a white tuxedo with a black tie, who was standing with Solange, then 28.

Speaking to the Daily Mail, Lopez detailed how the gown sparked the drama. He said: "I think that Jay complimented her about the gown and Beyoncé's sister felt that it was not proper, so it was a kind of a drama there."

A short time later, in the assumed privacy of an elevator, Solange could be seen laying into Jay-Z, until a member of his entourage manages to pull her off, with the Cranes in the Sky singer still lashing out with her heels.

In a statement issued after the incident, Jay-Z said that he and Solange 'assume their share of responsibility' for the fight and 'have apologized to each other,' allowing them to move forward 'as a united family.'

But many have assumed that this incident and the alleged affair with Roy is responsible for Beyoncé's smash hit Lemonade album, which unloaded on her husband for cheating on her with 'Becky with the good hair.'

Roy would later post a picture on Instagram with the caption 'Good hair don't care', but would deny that she was the Becky described on the album.

Naturally for designer Lopez, the incident only made more people pay attention to his work, with pictures of Roy in his black lace gown spreading around the world.

"Any press is good press," the Cuban artist told the Mail. 'It's good that people talk about you.

"Sometimes you benefit from a scandal, not even being part of it in a very direct way. Let's just call it a collateral damage. It was meant to be."