Even though Beyonce has recently took to Instagram to post several pictures of herself with her sister, Solange Knowles after she attacked Jay Z it looks like new information has surfaced following the reason behind the elevator fight.

Apparently Knowles was not too happy with Rachel Roy's close friendship with the "Holy Grail" rapper. According to Hollywood Life, a new report is alleging that Solange let her emotions get the best of her and approached the fashion designer in the Standard Hotel's Boom Boom Room on May 5th.

Upset about her public outburst the "On the Run" rapper confronted his sister-in-law and told her she was "out of line," which caused her to attack him in the elevator.

A source told Us Weekly, "Solange was yelling that anyone who gets close to Jay has to be warned and deal with her as a sister."

However, things went from bad to worse when Beyonce and Jay Z intervened and tried to get Solange to leave the party.

An insider revealed, "Jay said something small to her along the lines of, 'You are out of line,'" adding, "Solange was being a loudmouth and snapped at Jay for trying to calm her down and get her out of there."

The source added that "there were a few other things" said but insists that it "isn't the big deal people are making it into."

However, other sources are saying that the friendship is an issue with the couple but the "Drunk in Love" singer tends to down play her feelings on the matter.

An insider said, "Solange was defending Beyoncé in the elevator because Solange finds Jay's friendship with Rachel to be WAY too close for comfort and it makes Solange very uncomfortable."

The source went on to reveal, "Beyoncé also confronted Rachel and said, 'Don't talk to my sister like that,' after [Rachel] confronted Solange."

What are your theories on what happened that cause Solange Knowles to attack Jay Z? Let us know in the comment section below.