The Stockholm resident was part of a group of experienced potholers exploring a cave near the village of Cadrieu when a sudden flow of water swept him away.
Rescue workers spent an hour and a half giving him heart massage in the spot where his body had become trapped, partly under water.
The man later died when he was transported to a hospital in the nearby town of Cahors.
“He was swept away in a strong current. He died because he was under water for ten minutes,” Gérard Catala of the Cahors police told local media.
According to initial reports, the Swede was accompanied by two other countrymen at the time of the accident.
However, local police later told the Expressen newspaper that the Swedish man was part of a group that included two Germans and French guide.
Late on Monday night, the Swedish foreign ministry confirmed the accident.
“We can confirm that a Swedish man in his thirties died in an accident in France; that’s all we can say,” foreign ministry spokeswoman Victoria Bell told Expressen.