A former senior council official was the victim of constructive unfair dismissal, a tribunal has ruled.
In April last year, Alan Langridge resigned from his post, saying he was feeling "very ill" due to his treatment at Croydon Council, the Croydon Advertiser reports.
The 45-year-old had worked for the local authority - which employs around 10,500 members of staff - for nine years before his departure.
He claimed that the job turned into a nightmare.
Three months earlier, he had received a letter from the organisation's head of finance Nathan Elvery informing him someone else was being brought in to take over his role with immediate effect.
Commenting on this, tribunal judge Andrew Gumbiti-Zimuto said: "The appointment of Mr Blacker as an interim acting assistant director of finance had the effect of depriving the claimant (Mr Langridge) of any role or responsibility."
Croydon Council claims that its finances were in a serious state at the time it was decided to bring someone else in.
A further hearing will decide how much compensation Mr Langridge will receive.