A woman has had her arm bitten in a gruesome incident at a zoo after a lion lunged and "inexplicably" attacked her.
The Darling Downs Zoo said the woman, in her 50s, was watching keepers working in the carnivore precinct on Sunday when the lion grabbed her arm.
The zoo said the woman was not a keeper or staffer but "a much loved member of our family."
"This is something that she has done many, many times over the past 20 years. She is well versed in safety protocols around potentially dangerous animals," it said in a statement.
"Inexplicably, at this stage, one animal grabbed her by one arm and caused severe damage to it."
The zoo said the lion had not recently cubbed and would not be put down or punished in any way.
"At no stage did this animal leave its enclosure and there was no risk at all to staff members or members of the public," it said.
Emergency services were called to Pilton, south of Toowoomba, around 8.30am with the injured woman taken to Brisbane's Princess Alexandra Hospital where she was in "a stable condition".
The zoo closed for the day after the incident but was expected to reopen on Monday.
Police and Workplace Health and Safety officials confirmed to AAP they were investigating the incident to understand how it happened.
The 20-year-old zoo is a two-hour drive southwest of Brisbane and has a wildlife collection of lions, tigers and leopards from Africa and Asia.
