The three all attended the event last Monday before heading off to The Standard Hotel in New York for an after-party.
The video shows Knowles walking up to the rapper and brother-in-law and then punching and kicking him, while a bodyguard does his best to hold her back. At the end of the 58-second clip, Beyonce, 32, steps in between the two.
Jay Z, 44, seen in the video wearing in a white tux, which he wore to the Met, does his best to stand away from Solange in the corner of the elevator and just put his hands up in defense. Solange continues to kick him, even with the bodyguard holding her.
Reps for both parties have not yet responded to a requests for comment.
The alleged video looks to be surveillance video and the Standard Hotel sent a statement to The Grio on the matter.
"We are shocked and disappointed that there was a clear breach of our security system and the confidentiality that we count on providing our guests," the statement reads. "We are investigating with the utmost urgency the circumstances surrounding the situation and, as is our customary practice, will discipline and prosecute the individuals involved to our fullest capacity.”