Erick W. Rasco/Sports Illustrated/Getty
Famed soccer journalist Grant Wahl has died after he collapsed during a match in Qatar. He was 48.
The CBS Sports reporter was covering the FIFA World Cup in Qatar when he died Friday during the Argentina versus Netherlands game.
His cause of death is unknown, however, his brother Eric Wahl said he suspects foul play.
"My name is Eric Wahl. I live in Seattle, Washington, I am Grant Wahl's brother," he said announcing his brother's death on Instagram Friday.
"I am gay, I am the reason he wore the rainbow shirt to the World Cup. My brother was healthy, he told me he received death threats. I do not believe my brother just died. I believe he was killed, and I just beg for any help."
Grant Wahl/Twitter Grant Wahl
Wahl's wife, Cèline Gounder, said she's in "complete shock."
She tweeted as news of Gahl's death spread, "I am so thankful for the support of my husband @GrantWahl's soccer family & of so many friends who've reached out tonight. I'm in complete shock."
On Saturday, FIFA President Gianni Infantino expressed his "sincerest condolences to the family and friends" of Wahl.
"It is with disbelief and immense sadness that I have been made aware of the passing of renowned sports journalist Grant Wahl, whilst reporting on a quarter-final match during the FIFA World Cup in Qatar," Infantino said in a statement. "Only some days ago, Grant was recognized by FIFA and AIPS for his contribution to reporting on eight consecutive FIFA World Cups, and his career also included attendance at several FIFA Women's World Cups, as well as a host of other international sporting events. His love for football was immense and his reporting will be missed by all who follow the global game."
On the latest episode of his podcast, Fútbol with Grant Wahl, the journalist said he had bronchitis.
"My body told me, even after the U.S. went out, 'Dude you are not sleeping enough.' It rebelled on me."
He visited the clinic at the media center for the games twice, he said, and though he was feeling better he canceled all of his plans for Thursday.
U.S. Soccer released a statement via Twitter and said, "The entire U.S. Soccer family is heartbroken to learn that we have lost Grant Wahl. Fans of soccer and journalism of the highest quality knew we could always count on Grant to deliver insightful and entertaining stories about our game, and its major protagonists: teams, players, coaches and the many personalities that make soccer unlike any sport."
The organization saluted Wahl, stating that his "passion for soccer and commitment to elevating its profile across our sporting landscape played a major role in helping to drive interest in and respect for our beautiful game."
It went on to praise another trait of Wahl's, writing in part that "Grant's belief in the power of the game to advance human rights was, and will remain, an inspiration to all."
U.S. Soccer concluded by sending condolences to Wahl's family, stating that "his writing and the stories he told will live on."
Sports Illustrated, where Wahl worked for 24 years, also praised the late journalist.
In a joint statement, its co-editors in chief Ryan Hunt and Stephen Cannella said: "We're shocked and devastated at the news of Grant's passing. We were proud to call him a colleague and friend for two decades—no writer in the history of SI has been more passionate about the sport he loved and the stories he wanted to tell. Our hearts go out to Celine and his family, as well as everyone who loved his work. He will always be part of the SI family."
A representative from the U.S. State Department did not immediately respond to PEOPLE's request for comment.