"The @nfl Twitter account was hacked. @nflcommish is alive and well," league spokesman Brian McCarthy said. McCarthy confirmed to Reuters that the account had been hacked.
"We are reviewing and strengthening our cyber-security measures," McCarthy said in an email.
He said the NFL had contacted law enforcement about the hacking but declined further comment.
The NFL's official Twitter handle sent a tweet at 12:36 p.m. ET that read, "We regret to inform our fans that our commissioner, Roger Goodell, has passed away. He was 57. #RIP."
The tweet was promptly deleted, only to be followed by another rogue message, this time seemingly mocking the league.
"Oi, I said Roger Goodell has died," the tweet read. "Don't delete that tweet."
A Twitter spokesman declined to comment and directed inquiries to the NFL.
"Roger Goodell" quickly began to trend on Twitter, with some social media users cracking jokes.
"Fans across the nation devastated after hearing Roger Goodell was found alive this morning in his office at @NFL HQ. He is 57," tweeted Henry McNamara (@HenryLMcNamara).
The NFL was not the only high-profile account hacked this week.
Facebook founder Mark Zuckerberg's Twitter and Pinterest accounts were hacked on Sunday.
© Thomson Reuters 2016