A New York City hotel says it is investigating the leak of a security video that appears to show Beyonce's sister, Solange Knowles, attacking Jay Z.

Asked about the video on Monday by The Associated Press, The Standard Hotel issued a statement saying it is "shocked and disappointed that there was a clear breach of our security system."

TMZ posted the video and said it was shot last week inside an elevator at the hotel, where the three reportedly attended an after-party following the Met Costume Institute Gala. It appears to show Solange attacking Jay Z in Beyonce's presence. A security guard intervenes. There is no audio.

The hotel says the leaked video violates the confidentiality it provides customers. It says it "will discipline and prosecute the individuals involved to our fullest capacity."

Representatives for Beyonce, Jay Z and Solange didn't immediately comment.