India, Sept. 4 -- A proposed USD 4.2 billion investment deal involving FIFA's most valuable competitions has now grown into a full-blown legal dispute between world football's governing body and UEFA. On Thursday, FIFA accused European football's governing body of launching a "smear campaign" against president Gianni Infantino, at a time when UEFA is seeking access to documents linked to a plan that was withdrawn within days of becoming public.

The latest development came in a filing before the US District Court in Colorado on Thursday. FIFA asked to intervene in UEFA's discovery proceedings and argued that the requests should either be deferred or dismissed.

"While these applications are styled as legal pleadings with captions and dock...