Those supporting Afkari have accused police of torturing a confession out of him after finding the surveillance footage.
Paknia represents three men sentenced to death over links to similar protests in November, but the trio's execution was halted over a request to the supreme court to review the verdict.
Irna reported on Saturday that Afkari was executed after the victim's family refused to forgive him and allow him to pay restitutions.
But Iran ignored all calls for mercy towards Afkari, who was said to be framed and thought to be used to make an example out of him.
Iran broadcast the wrestler's confession on state TV last week. "He went to a peaceful protest in Iran, and he is gonna be executed for that". This guy is, first of all he's a human being; number two: he's one of us.
White, in hearing of the sentence, reached out to President Trump, who is a personal friend of his, for help. "He said "let us look into it, we'll talk to my administration and see if there is something we can do to save his life".
The 27-year-old was executed at a prison in Shiraz, according to IRNA.
On Tuesday, a global union representing 85,000 athletes called for Iran's expulsion from worldwide sports competitions if it executed Afkari, according to Reuters.
"Hearing that Iran is looking to execute a great and popular wrestling star, 27-year-old Navid Afkarai, whose sole act was an anti-government demonstration on the streets", President Trump tweeted on September 3.
Navid Afkari, 27, was executed at a prison in the southern city of Shiraz, provincial prosecutor general Kazem Mousavi was quoted as saying on state television's website.
Afkari's lawyer, Hassan Younesi told CNN that philanthropists had gone to the city of Shiraz and were trying to raise money to pay the restitution, but it was too late - the Shiraz judiciary informed Afkari's family the sentence was already carried out and they didn't get to say goodbye.
US President Donald Trump got involved last week, asking the Iranian leaders last to spare Afkari's life. They were protesting the 'country's worsening economic situation and inflation.
Iranian journalist Masih Alinejad wrote, "In a taped message from inside the prison, Navid said: 'If I'm hanged, know that an innocent man has been killed'".