The owners of a zoo where a woman was mauled by a lion are yet to determine what led to the attack.

The woman, in her 50s, was airlifted to Brisbane's Princess Alexandra Hospital on Sunday after being bitten by the lion at Darling Downs Zoo in Pilton, a small town in Queensland's Toowoomba region.

The victim, who remains stable in hospital, lost an arm in the attack that has shocked staff and the local community where the family-owned park has operated since 2005.

The zoo said late on Monday the woman, a relative of the owners, remained in hospital "and is surrounded by members of our extended family".

"She is a much loved member of the zoo owners' family," it said in a Facebook post.

"It has still not been possible to interview her to establish what led to this tragic incident."

The zoo said the woman was bitten by a lioness in an attack that did not take place inside the animal's enclosure.

"It was not hungry, skinny, taunted or tortured - it is a lion," the zoo said.

"It comes from a long line of captive born lions in Australia but it is still a lion - not a pet."

David Littleproud, MP for Maranoa, the federal electorate where the zoo is located, described the attack as "horrific".

"I encourage locals to continue to visit and enjoy the zoo, which will need support from the community during this difficult time," the Nationals leader said in a statement.

The zoo said on Sunday the woman was watching animal keepers work in the carnivore precinct when the "inexplicable" attack occurred.

"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.

The zoo is expected to reopen on Tuesday

It said the lion would not be put down or punished for the attack.

Queensland Police attended the zoo on Sunday, but said state workplace health and safety authorities were leading investigations. That work continued on Monday, a spokesperson said.

The zoo, the major venue of its kind in regional Queensland, houses tawny lions and white lions, both species native to South Africa.