Former Fifa president Sepp Blatter is being investigated over the mismanagement of a $1m loan given by Fifa to the Trinidad and Tobago Football Association in 2010.
In legal papers dated 13 May 2020 and seen by the BBC, Swiss federal prosecutors say Blatter is an 'accused person'.
It is the latest allegation of financial impropriety against Blatter.
The 84-year-old has always denied any wrongdoing.
The documents allege the interest-free and unsecured payment was made from a Fifa account on 13 April 2010. It adds the payment was subsequently waived.
Former Fifa general secretary Jerome Valcke and finance director Markus Kattner are also named as accused persons in the documents.
The Swiss investigation is being overseen by Thomas Hildbrand, who joined the federal team handling soccer investigations last year.