The pensioner was attending a private party at the Skansen Aquarium in Stockholm.
The man was bitten after he climbed up to make a speech in a part of the aquarium that was adjacent to the crocodile enclosure.
“He was stood with his back against the crocodiles with his arm stretched back over the protective barrier when the crocodile bit him,” a Skansen spokesperson said in a statement.
The spokesperson described the incident as a “tragic accident”.
“The extent of the injury is currently unknown,” the statement added.
“The incident is automatically reported to the police and the man has been taken to hospital.”
Mr Pettersson said: “He was heavily bandaged when we arrived on the scene.”
Skansen Aquarium has two Cuban crocodiles, named Castro and Hillary.
The pair arrived from Moscow Zoo in 1981.
Fidel Castro, the Cuban dictator, gifted the crocodiles to Vladimir Shatalov, a Russian cosmonaut, in the 1970s.
The gift was a sign of friendship between the communist nations.
“[Shatalov] brought them back to Moscow and he had them in his flat until his wife said: ‘No more!’ And then he had to give them to the zoo in Moscow,” said Jonas Wahlstrom, the zookeeper who raised Castro and Hillary.
Moscow Zoo did not have space for the reptiles and asked Mr Wahlstrom to take them to Stockholm.
“I had them as my hand luggage back from Moscow,” he said.
Castro and Hillary have had 11 children since arriving at Skansen Aquarium.
The aquarium has launched an investigation into the crocodile attack and is taking further action.
“Our thoughts are with the man and his family, who are affected by this very tragic accident,” the aquarium spokesperson said.
Police in Stockholm are also investigating the incident.
Additional reporting by agencies
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