Disgraced former FIFA president Sepp Blatter has admitted his six-year ban from all football-related activity has taken a toll on his mental health.

In an interview with German broadcaster ZDF to be screened Thursday night, the 80-year-old Swiss says the ban has left 'a mark' on him as he continues the fight to prove his innocence.

‘I've been marked by it, because of what happened to me, this attack on FIFA shocked me. I suffer to this day because of this blow,’ he said in the interview, filmed at his home in the Swiss canton Valais.

Blatter, who underwent treatment for skin cancer last month, has taken the fight to clear his name to the Court of Arbitration for Sport (CAS) against the ban, imposed on him and ex-UEFA president Michel Platini in December 2015 by FIFA's Ethics Committee, for a dubious payment of 1.8 million euros ($2m).

Blatter has always protested his innocence and is convinced his name will be cleared by CAS when his hearing takes place on August 25 in Lausanne, Switzerland.

‘I am not corrupt!’ insisted Blatter.

‘The whole situation will be clarified, and it will happen, I am 100 percent convinced of that: nothing will stick to Blatter.’

In December 2015, FIFA judges originally banned Blatter and Platini for eight years over the payment Blatter sent to Platini in 2011.

An appeals body at world football's governing body reduced their bans to six years in February, citing mitigating circumstances.

Blatter and Platini have claimed the funds were part of a legitimate verbal contract in connection with consulting work that Platini did for FIFA between 1999 and 2002.

Blatter is under criminal investigation in Switzerland over the transaction and other aspects of his management of FIFA.