Police are investigating the theft of Bill Kenwright’s panel from the Everton Timeline.
Kenwright’s 1999 takeover of the club had been displayed outside Goodison Park as part of a chronology detailing the history of the club.
But the image, which sat above the ticket office, was removed last Friday, just hours before the Blues’ Premier League encounter with Brentford.
Club officials described the incident as an act of criminal damage, which Merseyside Police has confirmed it is now liaising with Everton over.
“We are aware that a section of the ‘Everton Timeline’ was stolen from Goodison Park at around 10.15pm on Friday 10 March,” said a spokesperson for the force.
“We are liaising with Everton Football Club to help identify anyone involved and our enquiries are ongoing.”
Kenwright and his fellow board members have not attended any matches at Goodison since January 3 on security advice due to alleged safety concerns.
Everton claimed before their defeat to Southampton that the four directors had faced ‘a real and credible threat’ but did not report them to the police.
Fans have continued to protest against the absentee hierarchy under the banner of #AllTogetherNow and staged a number of pre-match marches.