A 33-year-old local caver who was knocked out unconscious by a falling rock while exploring a newly discovered cave near Cerknica has been rescued after 30 hours of efforts that also involved mining.

The woman was brought out of the Vranjedol Cave on a stretcher at around 4am on 17 April after mining teams expanded several narrow parts of the cave wide enough to let the rescue party pass.

She had been unconscious since a large stone fell on her head at the depth of about 100 meters at around 6:30pm on 15 April, piercing her helmet. A medical team descended into the chasm to provide her with emergency care.

After the miners did their job carefully expanding the passages with small amounts of explosives, it took rescuers four hours and five minutes to extract her on a stretcher from the site of the accident.

The stretcher, two metres long by 70 centimetres wide, had to be pulled up in an upward position.

Once brought out of the cave, she was transported to Cerknica, in south-central Slovenia, with an ambulance before an army helicopter took her to UKC Ljubljana.

"This way we ensured that she received medical care as quickly as possible and avoided the morning rush hour and the risk of further accidents," Sandi Curk, the head of the regional civil protection headquarters for the Notranjska region, told the STA.

He said the injured caver had normal pulse rate and blood pressure when she was brought out of the cave. Meanwhile, UKC Ljubljana told the STA the caver's injuries remained life-threatening and her condition unpredictable.

The woman, who is an experienced caver, was part of a group of six members of the Rakek speleology club who were exploring as yet unknown parts of Vranjedol Cave.

After she was hit unconscious by a falling rock, a member of the group climbed out of the cave to get help, while the others stayed with her and helped her. She was unconscious throughout, but a doctor found she was responsive to pain stimuli.

"They were on their on their way out of the cave when it happened. She was left unconscious hanging on the rope," Damjan Šinigoj, vice-president of the Slovenian Speleological Association and one of the first rescuers to reach the injured caver, told the tabloid Slovenske Novice.

"Four cavers suspended her to the ground, unfastened her from the rope and put her in the recovery position, while one climbed out to notify the Cave Rescue Service," he added.

More than 150 cave rescuers, medics, paramedics, miners and supply team members were involved in the effort in what has been described as one of the most demanding cave rescue missions in the country ever.