The Standard Hotel in New York City is investigating the leak of a security video, that appears to show Beyonce's sister attacking Jay Z.

The footage, obtained by TMZ, shows Solange Knowles hit out and kick Jay Z in an elevator, while being held back by a security guard.

The hotel says it's "shocked and disappointed" that its security system has been breached. Minutes after the footage was taken, Beyonce left the hotel with her sister while Jay Z travelled in a separate vehicle.

Last night, Jay Z and Beyonce put on a united front at a Brooklyn Nets basketball game. The couple have not commented publicly about the fight.