Former Birmingham co-owner David Gold has been banned from attending tomorrow's clash with his current club West Ham at St Andrew's.
Gold was initially told he would not be allowed in the director's box or boardroom but this ban has now been extended to the entire stadium.
Blues have taken this stance in response to Gold's comments in the Birmingham Mail today about the club he was in charge of for 16 years along with David Sullivan.
Gold described current City vice chairman Peter Pannu as "disgusting" in the article.
This referred to Gold's claims that he was denied the chance to remain as chairman of City by Pannu after he and Sullivan sold the midlands club to Carson Yeung for £8.5 million.
Pannu has been adamant Gold was never guaranteed such a role and he later rejected the chance to be a vice-president.
City initially sent a letter to the Hammers saying Gold will not be welcome in the directors box or boardroom tomorrow after his remarks.
It says the board "has taken the decision to withdraw Mr Gold's personal invitation to our fixture tomorrow.
"He will therefore not be permitted to enter the directors seating or boardroom area.
"The board feel that they are left with no other option but to withdraw Mr Gold's invitation and that this is the appropriate action to take.
"In addition, the board are also mindful of potential security issues for Mr Gold and a possible adverse reaction that may arise from the Birmingham supporters as a result of the comments made.
"Furthermore, as Carson Yeung will also be flying in for the game, the board felt that a harmonious boardroom environment should not be affected as we all want a good atmosphere on the day and a good game of football."
Birmingham then decided to extend the ban to the whole of the ground.
Gold admitted yesterday to the Birmingham Mail that he had "some trepidation" about attending the fixture.