LONDON — Keith Flint, a high-octane founding member of the British dance act the Prodigy, who sang lead vocals on the hits “Firestarter” and “Breathe,” was found dead on Monday in Essex, England. He was 49.

His death was announced on the band’s Instagram account. In a post on Monday, Liam Howlett, the band’s main musician, said Flint had killed himself.

“I can’t believe I’m saying this but our brother Keith took his own life over the weekend,” Mr. Howlett wrote, adding that he was angry, confused and heartbroken by the news.

The Prodigy was scheduled to tour the United States in May, with one show set for Terminal 5 in Manhattan. It has not been announced whether the shows will go ahead.