The home of a former Barclays Premier League referee has been searched by police over alleged anti-Catholic messages posted on his website after an Old Firm match.
Officers from Strathclyde Police searched Jeff Winter's house in Middlesbrough and seized "various items of equipment".
The investigation is into alleged anti-Catholic remarks posted on Mr Winter's website after Celtic defeated Rangers 1-0 last December.
A man was detained by police in London in connection with the investigation and was later released. The man was not Mr Winter, police said.
A spokeswoman for Strathclyde Police said: "Around 8am on Tuesday September 11 2012, officers from the national football co-ordination unit, acting under warrant, searched a house in Middlesbrough and seized various items of equipment.
"The search is part of an ongoing inquiry in connection with alleged offensive comments posted on a website.
"A further operation in London resulted in one man being detained by police and thereafter released. Enquiries continue."
The national football co-ordination unit was set up to police football matches across Scotland and to tackle problems associated with the game including disorder, violence, sectarianism and hate crime.
Mr Winter refereed hundreds of football matches in England, ending his career after the 2004 FA Cup Final between Manchester United and Millwall.