ZURICH: The legal complexities of the ISL controversy are surfacing again with a claim that the FBI is investigating the role of Sepp Blatter in the $100m scandal over the former FIFA marketing partner which went bankrupt in 2001.

A BBC Panorama documentary to be screened tonight reveals a letter – obtained by the FBI, and forwarded to Swiss authorities with a request for help – in which former world federation president João Havelange appears to say: “Mr Blatter had full knowledge of all activities,” and was “always apprised to them”.

The FBI’s request was sent before the dramatic arrests in May this year which prompted Blatter’s reluctant impending departure.

In a covering note to the Swiss authorities the FBI requests information from an earlier Swiss investigation into the ISL scandal, which involved illicit payments by ISL to senior FIFA officials.

The note adds: “Among other things, the prosecutor is investigating Havelange’s statements implicating Blatter and appearing to exculpate Havelange’s son-in-law, [Ricardo] Teixeira, in the ISL matter.”

In the letter from Havelange, seemingly written after a 2010 court case in Zug, Switzerland, related to the affair, he appears to claim that payments to him were above board.

He writes: “During the period of time in which I was FIFA president, Mr Joseph Blatter was the secretary general, I maintained commercial relationships with sports marketing companies which were under my economic control, and, as a result of these relationships, I received remuneration, in accordance with Fifa regulations, and this was the object of a judicial proceeding settlement in Switzerland without acknowledgement of any guilt.

“I clarify that all expenses for the mentioned proceeding, including attorneys, were paid by FIFA. I emphasise that Mr Joseph Blatter had full knowledge of all activities described above and was always apprised to them.”

The BBC says that Blatter’s lawyers have failed to respond to a request for comment.

Havelange resigned from his position as the honorary Fifa president in 2013 after an ethics committee report confirmed how he and Teixeira, his former son-in-law, had taken a series of bribes over an eight-year period.

However such payments, until 2004, were not illegal under Swiss law and thus Havelange was not guilty of criminal behaviour.

Teixeira, Havelange’s former son-in-law, was one of three former heads of the Brazilian FA named among an additional 16 people charged with corruption offences by the US Department of Justice last week.

The programme is also told by the former FA chairman Lord Triesman that he was told Qatar spent £117m on its bid to win host rights to the 2022 World Cup.

It has long been accepted that Qatar spent as much or more on promotional activities than all the others bidders put together.