Essex President John Faragher resigned following an accusation that he used racist language at a 2017 board meeting.
Faragher strongly denies the allegation, but Essex says they will review why the matter was not fully and independently investigated at the time.
He retired from his post after a board meeting on Thursday.
“There is no room for discrimination of any kind at the club,” said CEO John Stephenson.
Former Essex starter Stephenson, who only took over the daily running of the county in October, said he first learned of the alleged incident this week.
“I learned of this single allegation on Thursday,” he added.
“The board met last night [Thursday] during which John Faragher’s resignation was accepted unanimously.
“This is a proud club with a zero tolerance policy towards racism and any form of discrimination. I will not hesitate to uphold those principles and eliminate any form of discrimination that is discovered.”
Faragher, who was named president of Essex in 2016, oversaw two county championship titles in 2017 and 2019, a T20 Blast win also in 2019 and the county lifting the Bob Willis Trophy in 2020.
His resignation comes in the wake of a racism scandal in Yorkshire involving former player Azeem Rafiq.
A report found that Rafiq was the victim of “racial harassment and intimidation,” but the county said it would not discipline anyone, leading to widespread condemnation.
However, a series of resignations has followed including CEO Mark Arthur and President Roger Hutton.