Swiss investigators concluded Sepp Blatter knew that a World Cup broadcasting contract was breached illegally and that it would cost FIFA millions, according to a federal police file obtained by The Associated Press.

Investigation reports sent to prosecutors in December and January showed FIFA wrote off a $US3.8 million ($5.83 million) debt from a Caribbean TV deal signed in 2005 by then-FIFA president Blatter and long-time vice president Jack Warner.

The deal was later alleged to have been illegally mismanaged by Blatter.

“Blatter acted more in the interests of Warner than in the interests of FIFA,” concluded one investigation file seen by the AP.

However, the office of Switzerland’s attorney-general decided in March it would drop a criminal proceeding from 2015 against Blatter for the Caribbean deal.

No reason was stated.

Swiss federal police believed Blatter knew in 2007 that Warner had breached – and would personally profit from – a Caribbean rights deal for the 2010 and 2014 World Cups that was sold to a Jamaica-based broadcaster.

Details of the original FIFA contract were revealed by Swiss media in September 2015, showing a $600,000 ($928,000) sale to the Warner-controlled Caribbean Football Union.

At the time, FIFA defended the contract by saying it required soccer’s governing body to get a 50 per cent profit share of any future licensing arrangement.

The re-sale was valued about $US15 million ($23.02 million).

But FIFA did not try to collect money due in August 2010 within 30 days of the World Cup ending, according to the Swiss police file.

The investigation cited documents and staff emails showing FIFA was due half of any gross revenue from the Caribbean deal, into which Warner had inserted a company he owned.

“FIFA were very reluctant to implement any measures in connection with enforcing their rights against the CFU,” Swiss police said in its 491-page report.

FIFA calculated it was owed almost $3.8 million ($5.83 million) in 2011 after Warner resigned from soccer.

He had been implicated in bribing Caribbean voters to oppose Blatter in that year’s FIFA presidential election.

Only then did FIFA management terminate the Caribbean rights and pursue the debt, though not directly with Warner.

Instead, it asked the CFU, which had few assets after Warner left.

FIFA wrote off the debt weeks later, the police file showed.

Blatter, who is now 84 and banned from soccer until October 2021, did not immediately respond to a request for comment.

He has long denied wrongdoing.

-AAP