The man has not been named, but eyewitnesses described seeing a man in his 20s on the walkway at the tiger enclosure, wearing headphones and “pacing around” minutes before the incident took place.
South Yorkshire Police confirmed he was visiting the park on his own.
Speaking to the BBC, Ella Ford, 24, from Wirral, said she saw the same man had climbed up onto the barriers and was spoken to by a woman before “he jumped in and crawled in front of the tiger, where the tiger was perched and just lay there”.
Ford said she then saw the man shouting for help and the tiger grabbed hold of him.
She estimates about 15 to 20 people were on the enclosure’s raised visitor walkway before staff quickly evacuated the area, and shortly afterwards, the park.
People nearby were confused, she said, and one man was “trying to bang on the fence to try and deter the tiger away, but it obviously wasn’t doing anything”.