Birmingham have confirmed assistant manager Terry McDermott and first-team coach Derek Fazackerley have left the club by mutual consent.
Reports first emerged almost two weeks ago suggesting the pair had left St Andrew's but the Championship club have made no official comment, with legal ramifications involved.
Blues boss Lee Clark, unable to go into too much detail, last week insisted the departed duo had not been sacked and dismissed any speculation over involvement from the club's board.
The duo were absent from the bench for last Saturday's 2-1 victory at Blackpool, where Clark - reportedly keen on a fresh approach - was flanked by an existing backroom team of Steve Watson, Richard Beale and John Vaughan, who will each remain in place.
But Birmingham have now verified McDermott and Fazackerley's departures, adding that it was not a cost-cutting measure.
Clark said: "The three of us have been having amicable discussions and we all decided that it was in the best interests of all parties for Terry and Derek to part ways from the football club.
"This certainly wasn't a decision imposed by the board, who have been very supportive, but a conclusion Terry, Derek and I reached following the discussions.
"I have known Terry and Derek for many years and they both remain good friends. I would like to take this opportunity to thank them for their loyalty, friendship and work ethic during my time as a manager with both Huddersfield Town and Birmingham City."