“The man had been driving a water tanker when he stopped to take a photograph with the animal.
“The wild elephant attacked the man and killed him,’’ the officials said.
The wild elephant was part of a herd moving from the western to the eastern part of the reserve, an annual movement during the monsoon.
A herd of 21 jumbos made the movement on Tuesday.
The elephants disrupted traffic on the highway that passes through the forest for several hours.
There are 65 elephants in the Parsa Wildlife Reserve and around 170 total wild elephants in the country.
About the same number are kept as working elephants at tourist resorts and government-run breeding centres.
Deaths from elephant attacks are not uncommon in southern Nepal’s buffer zones near forest areas.