A tourist in Tasmania has had his leg amputated in the middle of a raging river after getting trapped between rocks during a kayaking trip with friends.

Medics said they made the “life or death” decision in consultation with the international visitor during a complex rescue on the Franklin River lasting some 20 hours.

The visitor in his 60s was partially submerged in water throughout the ordeal, and rescuers said it was clear that “had he remained in the location where he was, and trapped in the rock crevice he would not have survived”.

Multiple attempts to move him prior to the amputation were unsuccessful, police in the Australian island state said.

The tourist was kayaking with a group in the south-west of Tasmania when his leg got stuck between rocks in an area of rapids on Friday afternoon.

Emergency services rushed to the remote and inaccessible area after the man’s smartwatch called for assistance, police said.

After a number of unsuccessful attempts were made to free the man overnight and as his condition deteriorated, the decision was made to amputate his leg so he could be winched from the location and airlifted to hospital.

“This rescue was an extremely challenging and technical operation, and an incredible effort over many hours to save the man’s life,” Doug Oosterloo, acting assistant commissioner at Tasmania Police, said in a statement.

“This was a life and death situation,” Oosterloo told Australian national broadcaster ABC.

The man is now in a critical condition in hospital.

Oosterloo said that though the kayaker was “well prepared”, he wasn’t prepared for spending “that significant amount of time in a rock crevice with that temperature and the torrent of water that was he was under”.

The other 10 travellers who were kayaking with the man were being airlifted from the area and police plan to speak to them about how the accident happened, the Australian Associated Press reported.

Oosterloo told the news agency that the tourists had stopped kayaking and were on the shore when the man slipped.

“He was scouting the area and he slipped and fell into that rock crevice,” Oosterloo said.