Celtic have parted company with first-team coach Alan Thompson, according to his lawyer.
The 38-year-old joined the Hoops' backroom staff when former Celtic Park teammate Neil Lennon was appointed manager in June 2010, but has now been relieved of his duties.
It has been reported that there was concern within the club regarding his lifestyle.
Thompson was banned from driving and issued with a £600 fine after admitting a charge of drink driving in February 2011.
It is not yet clear whether the Englishman, who was on a one-year rolling contract, will take legal action against the decision.
Margaret Gribbon, Thompson's lawyer, broke the news in a statement, which read: "I can confirm that I have been instructed to act on behalf of Alan Thompson following his dismissal by Celtic FC.
"Alan was informed of the decision to terminate his employment with immediate effect in a telephone conversation with the club manager Neil Lennon."
Thompson won four league titles and three Scottish Cups while playing for Celtic between 2000 and 2007.