Retired Super Bowl winning quarterback Brett Favre has announced he has been diagnosed with Parkinson’s disease, speaking to a US congressional committee as part of his testimony about a welfare misspending scandal in Mississippi.

Favre, who does not face criminal charges, has repaid just over $US1 million ($1.4 million) in speaking fees funded by a welfare program in the state and was also an investor in a biotech company with ties to the case.

The biotech firm has said it was developing concussion treatments.

The former NFL MVP, 54, told the committee that he lost his investment in the company that he thought “was developing a breakthrough concussion drug I thought would help others”.

“As I’m sure you’ll understand, while it’s too late for me — I’ve recently been diagnosed with Parkinson’s — this is also a cause dear to my heart,” Favre said.

What causes Parkinson’s disease is unknown, and it is unclear if Favre’s disease is connected to his football career or head injuries.

He said on a radio show in 2022 that he estimates he may have experienced “thousands” of concussions in his two decades in the NFL.

According to the Parkinson’s Foundation, scientists believe that the disease is caused by a combination of genetic and environmental factors, and those environmental factors “may include head injuries, pesticide exposure or area of residence”.

Favre “is one of the 90,000 people in the US who will be diagnosed with PD this year alone,” said Parkinson’s Foundation CEO John Lehr.

In the 2022 interview, Favre said he initially thought the number of concussions he had received playing football was low, but realised it could be much higher once he learned more about them, including that they can happen without causing someone to lose consciousness.

During one 2004 game, Favre sustained a concussion but returned after sitting out only two plays and threw a touchdown pass without having been cleared to return to action.

Favre appeared at the Republican-led House Ways and Means Committee hearing to advocate reform of the US federal welfare system to better prevent fraud.

“The challenges my family and I have faced over the last three years — because certain government officials in Mississippi failed to protect federal TANF funds from fraud and abuse, and are unjustifiably trying to blame me, those challenges have hurt my good name and are worse than anything I faced in football,” Favre said.

House Republicans have said the scandal in Mississippi points to the need for an overhaul in the federal Temporary Assistance for Needy Families program. Favre says he provided services to the nonprofit that paid him with state funds, but the state auditor has said Favre did not show up for the speaking engagements.

Favre has said he did not know the payments he received came from welfare funds and has noted his charity had provided millions of dollars to poor kids in his home state of Mississippi and in Wisconsin, where he played most of his career with the Green Bay Packers.

Favre was known for his durability during his Hall of Fame career. He had an NFL-record streak of 297 consecutive starts, a figure that goes up to 321 if play-off games are included.

He won three straight MVP awards with the Green Bay Packers from 1995-97. Favre led the 1996 Packers to their first Super Bowl title in nearly three decades and brought them back to the Super Bowl the following year.

Favre was with Green Bay from 1992-2007 and also played for the Atlanta Falcons (1991), New York Jets (2008) and Minnesota Vikings (2009-10). At the time of his retirement in 2011, Favre owned multiple NFL career passing records. He was inducted into the Pro Football Hall of Fame in 2016.

AP