A Swiss court has ruled that the way FIFA fired its acting secretary-general Markus Kattner in 2016, when the scandal-ridden body dismissed him without notice over allegations of financial mismanagement, was unjustified.

In a verdict issued last October but only made public on Tuesday, the supreme court of the Swiss canton of Zurich -- where world football's governing body has its headquarters -- ruled that the firing of the German national was abusive.

Kattner's sacking without notice was "considered as unjustified" by the cantonal supreme court, a court spokesman told AFP.

That ruling overturned an earlier finding by the lower labour court in Zurich, he said.

Zurich's highest tribunal sent the case on to the labour court to rule on what damages should be awarded to Kattner, 52, who is reportedly seeking 10 million Swiss francs ($10.8 million) in compensation.

Kattner, who served for more than a decade as FIFA's finance director, took over as interim secretary-general in September 2015, after Frenchman Jerome Valcke was pushed out over a scandal involving tickets resold on the black market.

But less than a year later, Kattner himself got the axe.

FIFA fired him with immediate effect on May 23, 2016, saying an internal investigation had shown "failures" in the way he had carried out his financial duties.

FIFA accused him of providing himself and close associates with significant bonuses, set up under secretive terms, with the knowledge and authorisation of only a few people in the institution.

Among other things, the organisation alleged that he had breached a range of agreements and illegally obtained an audio recording of a meeting.

The Zurich supreme court ruled though that procuring a recording of a meeting he had been excluded from did not constitute valid grounds for a dismissal without notice.

Kattner's firing was only one in a string of episodes that rocked FIFA after the biggest scandal in the history of world football erupted on May 27, 2015, when Swiss police marched into a Zurich hotel and arrested, on US warrants, seven high-level officials.

Under pressure, disgraced long-time president Sepp Blatter announced a few days later he would resign, with current chief Gianni Infantino elected to succeed him in February 2016, just weeks before Kattner was let go.

Blatter had come to Kattner's defence at the time of his sacking, telling AFP in an interview at the time that he had "never met a more honest man".

Beyond his termination, Kattner was also hit in June 2020 with a 10-year ban from all football-related activities and a stiff fine of one million Swiss francs.

That punishment was handed down by FIFA's ethics committee, which following an internal investigation into the bonus payments ruled that Kattner was guilty of conflicts of interest and abusing his position.