Manager George Burley has dramatically parted ways with Premier League leaders Hearts because of "irreconcilable differences" with the Tynecastle board.
Hearts chairman George Foulkes said it had been "mutually agreed" that Burley would leave with "immediate effect".
Foulkes refused to comment further, citing a confidentiality agreement signed by Burley and the club.
Burley, 49, arrived at Tynecastle in the summer and leaves with Hearts unbeaten and top of the SPL table.
Throughout his short reign, rumours persisted about an uneasy relationship between Burley and major shareholder Vladimir Romanov.
The sensational news comes the day after Romanov announced a bid to take private control of the club.
Hearts coach John McGlynn took control of the first team for Saturday's 2-0 win over Dunfermline.
And he will remain in charge until a replacement is found.
"It is important that we look to the future," continued Foulkes. "The club is greater than any individual.
"We want to compete with Celtic and Rangers for a Champions League place and we will take the time necessary to find a top class manager.
"Naturally, I'm not happy at having to make this statement but there is no point looking to the past.
"We are determined to go from strength to strength."
Burley resigned his post at Derby County in June claiming his position was "untenable" after falling out with director of football Murdo Mackay.
At the time, Derby chairman John Sleightholme accused him of not making clear "his real reasons" for stepping down.
Burley moved to Tynecastle and set about rebuilding a team with the help of Romanov's considerable personal funding.
Unusually, Romanov himself identified several of Hearts' new faces, although Burley was adamant that he had "total control over selection".
Romanov, who now owns 55.5% of the shareholding at Hearts, arrived at Tynecastle in February.
And John Robertson resigned as manager in May after just seven months in the job.
Robertson, now boss at Ross County, was offered a lesser coaching role by Romanov but chose to step down.