A dispute has arisen over a dolphin rescue in Newfoundland, with one expert saying the men who were first hailed as heroes actually did more harm than good.

The mammals had been trapped in a small breathing hole in White Bay, unable to find their way under the ice out to open water.

The group of fishermen from Seal Cove, N.L. cut a trench more than 200 metres through the ice in order to create an exit path for the three trapped white-beaked dolphins.

The men, and the mayor of the town, said two of the dolphins swam to open water once the channel was finished, and the third was pulled out to sea, where it swam away.

But Wayne Ledwell, an expert on rescuing trapped whales, said he believes at least two of the dolphins are dead because they wouldn't have been able to navigate the icy waters of White Bay.

The Canadian Press cited Ledwell as saying he could only confirm one of the mammals was alive.

Ledwell, who has helped free trapped whales for 20 years, said its unlikely the dolphins will survive.

"In my opinion, the chances for survival would be slim," Ledwell, who runs a non-profit organization called Whale Release and Stranding, said/

"Even if you still do save them or you still do get them out to free water, you can't say for sure that those animals are going to survive. It's an extreme amount of stress on those animals."

But Brandon Banks, one of the rescuers, told CTV Newsnet that the dolphins would have perished if the men hadn't taken action.

Banks, who donned a dry-suit and jumped into the water to attach a harness to one of the dolphins so that it could be pulled to safety, maintained it was a good news story.

"They all would have died there at the same time so we had to go out there and try to do something and save a few rather than none," the 16-year-old said.

Winston May, mayor of Seal Cove, N.L., praised the men for their initiative.

He told CTV's Canada AM that local residents had set up a 24-hour vigil after discovering the dolphins.

"Even at nighttime there were people down there with big spotlights and the dolphins themselves were just crying and screeching for someone to come and help them," May said.

Residents took action

Local residents of the town on the western side of the Baie Verte Peninsula had requested official help from the Department of Fisheries and Oceans, but eventually got tired of waiting and decided to take action.

Two fishermen recruited some friends, then dug their boat out of a snow bank -- May said it was buried under about four feet of snow -- donned survival suits and got to work.

The men chopped through the ice, which was between three and four inches thick, little by little until they reached the dolphins.

"It was very traumatizing for a moment there because of course after those mammals had been there for four days they were pretty stressed out and I guess they got a little scared," May said.

Two of the mammals followed the boat out to open water. The third was too tired to move through the channel, so Banks went into the water to help, May said.

The teen fastened a harness to the dolphin, and when the boat returned, the fishermen pulled the mammal through the channel to safety.

Fourth dolphin

Earlier, a fourth dolphin had been seen with the group but by Thursday morning it had disappeared. May said it was unclear whether that dolphin had escaped during the night or perished under the ice.

"Whether it got away the night before or something happened to it we don't know. The night before we had a fair amount of storm and there was quite a bit of wind and the ice did kind of open up into little lakes of water in some places," he said.

"Whether it was strong enough to swim to one of those lakes of water and then on to the open ocean, we don't know."

White-beaked dolphins are year-round visitors to the Newfoundland coast and it is not uncommon for them to become trapped in the coastal ice.

They are typically about 2.5 metres in length and weigh about 180 kilograms.

Seal Cove in a small town of 300, about 600 kilometres northwest of St. John's.