Jay Z 'attacked by Beyonce's sister in lift'

A New York boutique hotel is investigating how a recording of a security video that purportedly shows rapper Jay Z being attacked by his sister-in-law, R&B singer Solange Knowles, was leaked to a website.

The video posted by celebrity website TMZ.com appears to show the 27-year-old Knowles, younger sister of Beyonce, charging and striking Jay Z several times in an elevator at the Standard Hotel in New York's Meatpacking District before being restrained.

Beyonce looks on in the three-and-a-half-minute video without audio, which quickly became an internet sensation, sparking several parody videos and photos.

The three are seen dressed in clothing that they had worn to the Met Gala benefit on the night of May 5. But representatives for all three did not immediately respond to requests for confirmation of the incident.

The hotel, the venue for a post-gala party, promised to prosecute whoever was behind the recording, calling it a breach of security and guest confidentiality.

"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," the hotel said in a statement without naming Jay Z, Beyonce or Solange Knowles.

The Standard Hotel, which has locations in Los Angeles and Miami Beach, Florida, is controlled by hotelier Andre Balazs' Standard International management company.