The brother of recently deceased American sports journalist Grant Wahl has gone private on Instagram after speculating his brother was killed.

Wahl, 48, died after he "fell ill" at Lusail Stadium in the final minutes of a FIFA World Cup quarterfinal game between the Netherlands and Argentina Friday, a Qatari spokesperson said.

Grant Wahl, 48, working in Qatar in a rainbow shirt that prompted security outside the U.S.-Wales match to detain him for 25 minutes. (Getty Images )

The veteran soccer journalist had bronchitis and had visited a medical clinic twice in the days before his death, he revealed in a podcast episode. Wahl was laughing with colleagues just minutes before his sudden death, an eyewitness said.

Wahl had previously been blocked from entering a stadium while wearing a rainbow-colored shirt.

AMERICAN SOCCER JOURNALIST GRANT WAHL DIES WHILE COVERING FIFA WORLD CUP IN QATAR

Soccer player Jozy Altidore, left, and journalist Grant Wahl attend the 2017 St. Luke Foundation for Haiti benefit hosted by Kenneth Cole at the Garage on Jan. 10, 2017, in New York City. (Mike Lawrie/Getty Images)

Eric Wahl announced his brother's death on Instagram and made an emotional plea for help. 

"I am gay. I am the reason he wore the rainbow shirt to the World Cup," Eric Wahl said. "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'm just begging for any help." 

Eric Wahl has now taken his Instagram profile private.

AMERICAN SOCCER JOURNALIST 'LAUGHING AT A JOKE' ON TWITTER MINUTES BEFORE COLLAPSE, WITNESS SAYS

Soccer journalist Grant Wahl and his wife, Dr. Céline Gounder. (Michael Loccisano/Getty Images for Budweise)

Just a day before his death, Grant Wahl published a scathing criticism of Qatar's government and the Supreme Committee for Delivery & Legacy, asserting indifference to the deaths of workers who built the World Cup stadium.

"The Supreme Committee in charge of Qatar’s World Cup doesn’t care that a Filipino migrant worker died at Saudi Arabia’s training resort during the group stage. He suffered a fatal blow to the head during a fall in a forklift accident (information that was kept under wraps until being broken by The Athletic’s Adam Crafton)."

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Grant Wahl with a World Cup replica trophy in recognition of his achievement covering eight or more FIFA World Cups, Nov. 29, 2022, in Doha, Qatar.  (Brendan Moran/FIFA/FIFA via Getty Images)

The Qatari Supreme Committee for Delivery & Legacy released a press statement acknowledging Wahl's death.

The committee said it is cooperating with U.S. officials to return Wahl's body to the U.S.

WHD News's Joseph A. Wulfsohn contributed to this report.