Leaked: Video shows Beyonce's sister violently attack Jay-Z

US entertainment website TMZ , has put out a video showing Jay-Z getting attacked by sister-in-law, Solange Knowles, in a lift in the presence of his wife Beyonce. You can watch the full video above. According to TMZ, “the incident took place at a Met Gala after party last week at the Standard Hotel in NYC." The video, whose authenticity we can’t vouch for, shows Jay Z, Beyonce and Solange step into the elevator together. Within moments of it, Solange is seen screaming at the rap mogul before starting to kick him, while shouting at him the whole time. She’s eventually stopped by someone appears to be a bodyguard, but she still manages to attack Jay Z about three times despite being held by the guard. [caption id=“attachment_1521181” align=“alignleft” width=“380”] Jay-Z and Beyonce at the Met Gala. AP[/caption] Solange is also seen pointing at Jay-Z while Beyonce stood between the duo. Beyonce isn’t attacked by her sister, but she does try and break up the fight. Meanwhile the Standard Hotel in New York City says it is investigating the leak of the security video. Asked about the video on Monday by The Associated Press, the hotel issued a statement saying it is “shocked and disappointed that there was a clear breach of our security system.” The hotel says the leaked video violates the confidentiality it provides customers. “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.” Representatives for Beyonce, Jay Z and Solange didn’t immediately reply to emails seeking comment, according to Associated Press. With inputs from AP