A hooligan who ran on to the pitch and assaulted a goalkeeper during a Championship football match has been identified by police.
The suspect, who has been named on social media sites but not by police, has yet to be arrested after former England goalkeeper Chris Kirkland was shoved in the face amid ugly scenes at the game between Sheffield Wednesday and Leeds United at Hillsborough on Friday night.
The FA is also investigating crowd trouble at the Yorkshire derby and is awaiting the referee's report.
Kirkland, who was playing for Sheffield Wednesday, was assaulted by the Leeds fan after the visitors had equalised.
The shocking scenes were broadcast live and fans were quick to condemn the trouble on Twitter and Facebook. That led to a suspect being named on sites, and a mobile phone number being circulated.
South Yorkshire Police's senior investigating officer, Detective Inspector Mark Monteiro, said:
An FA spokesman said: "We have begun an immediate investigation and have been in contact with both clubs.
"We would call for the authorities to identify and bring before the courts anyone who was involved in any form of criminal disorder."
Kirkland required medical treatment before he could continue.