West Bromwich Albion have launched an investigation after Wolverhampton Wanderers fans filmed themselves urinating on the pitch following the conclusion of yesterday's Black Country derby.
The two-minute YouTube video, called 'West Brom v Wolves 2011: P***ing On Your Pitch', shows two fans running onto the Hawthorns' turf in daylight.
West Brom triumphed over visiting Wolves 2-0 courtesy of goals from Chris Brunt and Peter Odemwingie.
Watch a video of the incident below: Warning, explicit content.
