The 'Losing You' singer - who appeared to attack her brother-in-law in a lift in New York's Standard Hotel while attending an afterparty for the Met Gala last Monday (05.05.14) - was reportedly seen yelling at fashion designer Rachel Roy earlier in the evening.
The mother-of-one's famous sibling Beyonce, 32, ''got in the middle of it'' to cool the situation, an onlooker tells Us Magazine.
However, another source claims Solange yelled at numerous people, including Rachel, who was once married to Jay Z's former friend and business partner Damon Dash.
Surveillance footage emerged yesterday (12.05.14) of Beyonce's enraged younger sister hurtling towards Jay - real name Shawn Carter - in the lift, landing a series of punches and kicks while the 'Drunk in Love' singer stood back out of the fray.
It's not known what caused the heated altercation between Solange, 27, and the 44-year-old rapper, but all parties have remained tight-lipped about the incident.
A source said: ''Beyonce tried to stay out of it. She does not approve of violence. They are trying to put the situation past them now.''
Prior to the drama, Beyonce, 32, and her younger sister were seen dancing up a storm on the dancefloor with supermodel Naomi Campbell, while Jay - who has two-year-old daughter Blue Ivy with his spouse - ''hung back at one of the fireplace areas''.
Despite the controversial video, Beyonce and her husband were spotted last night at a basketball game between the Brooklyn Nets and the Miami Heat at the Barclays Centre in New York and appeared relaxed and carefree.
Take a look back at October's inaugural event.
The film is expected to continue without Mendes' involvement.