Video of Jay Z violently attacked by Beyonce's sister, Solange.

According to sources, it all went down at a Met Gala after party last week at the Standard Hotel in NYC. In the video Jay Z, Beyonce and Solange step into the elevator and then Solange goes crazy, screaming at Jay before unleashing a violent attack.

TMZ says Jay Z was ferociously attacked by Beyonce’s sister Solange … who was wildly kicking and swinging at him inside an elevator and the attack was captured on surveillance video.

At one point, Solange even smacks Jay with her purse ... spilling the contents all over the floor of the elevator.Eventually, the group exits the elevator ... but not before Solange takes a few last shots. 

A large man — who appears to be a bodyguard — attempts to hold Solange back, but she manages to connect at least 3 times. At one point Solange throws a kick and Jay grabs her foot, but never attempts to strike her. Beyonce stands by without getting physically involved.She remained through out the fight and at one point calmly removed the long train of her dress from the fray.

It’s unclear what triggered the fight.

And this is interesting. When you look closely, you see the bodyguard hit the emergency stop switch on the 12th floor — mid fight — presumably to keep the fight private.

These photos were taken as they left the party and JayZ looks quite ruffled and Solange 

looks mad.

Jay Z and Beyonce left in separate cars, Bey departed with her sister.

What could have caused this kind of rage? See video below:

It's not yet known what provoked the fight, however, the famous couple looked as happy as ever as they attended a Brooklyn Nets game on Saturday while Solange played a gig in New York.

Solange has admitted to issues with drugs in the past, and cancelled her European tour last year amidst rumours of usage... according to Radar Online.

Two days after the violent row Beyonce shared the prayer below on her Instagram: