Blatter apparently stepped down from the post on June 2 just days after getting re-elected for a fifth four-year term under pressure from various quarters following the outbreak of a global corruption scandal within the world football's governing body.
"I did not resign. I put myself and my office in the hands of the FIFA congress," the BBC quoted the Swiss newspaper Blick as saying on Friday.
Blatter reportedly said this at a party at FIFA museum recently and is believed to be preparing to stand for re-election as president.
"While I have a mandate from the membership of FIFA, I do not feel that I have a mandate from the entire world of football," he said in his speech on June 2.
"Therefore, I have decided to lay down my mandate at an extraordinary elective congress. I will continue to exercise my functions as FIFA president until that election."
While the world viewed the speech as his farewell address, he did not use the words "resign" or "resignation".
He has since reportedly said he has not resigned but simply laid his presidential duties to FIFA's Congress, which will hold an election to determine the next president on December.
Nine FIFA officials among 14 people are indicted by the United States authorities for financial wrongdoing in a corruption scandal, which is also investigating the role of Blatter.
Swiss authorities have also begun an investigation into FIFA's bidding process to award the hosting rights of 2018 and 2022 World Cup to Russia and Qatar, respectively.