An injured and abandoned baby humpback whale that spent nearly a week bonding with boats in waters off north Sydney was euthanized by wildlife officials Friday after veterinarians determined it was too weak to survive on its own.

The plight of the whale calf, nicknamed "Colin," dominated news coverage in Australia since Sunday when it was first sighted and began trying to suckle from boats it apparently mistook for its mother.

National Parks and Wildlife Service spokesman Roger Bell said officials gave the 1- to 2-month calf an anesthetic in the water before hauling it onto the beach, and administering a lethal drug early Friday. The body was to be examined at Sydney's Taronga Zoo.

"It went very, very smoothly and professionally. The whale suffered as little as possible," he told The Associated Press.

• Click here for more pictures.

• Click here to visit FOXNews.com's Natural Science Center.

The 14-foot-long animal could be seen thrashing underwater as officials tried to sedate it close to the shore. Workers reached out to stroke the struggling creature as they towed it to the beach, where they hoisted the 2-ton animal onto a tarp and pulled it into a tent.

They hung gray tarps around the animal's body to block the view of journalists in small boats nearby.

"Shame! Shame!" cried Brett Devine, a marine salvage and rescue worker who had hoped to halt the euthanization and feed the whale a milk and krill concoction via a tube.

"It's shameful what we've done here today," he said, watching from his boat.

Maritime police boats patrolled the waters to keep the public and media from approaching.

"It's a very sad day," said Sally Barnes, deputy director-general of the New South Wales Department of Environment and Climate Change. "He is out of his misery."

Steve Coleman, an official with the RSPCA, said the whale needed to be destroyed and that it was done humanely. "It was cruel to keep it alive," he said.

Officials believe the calf was abandoned by its mother, possibly because it was ill. Wildlife officials said it appeared the whale had also been attacked by a shark.

An initial exam of the whale's body on Friday suggested it was a female, rather than a male, as first thought, Barnes said, adding that perhaps the calf's nickname should be changed from Colin to "Colette."

The parks service was investigating reports of an adult whale carcass being eaten by sharks off the southern state of Victoria on Friday, Barnes said. Officials hoped to collect a DNA sample to determine if it is the missing mother.

The baby whale had spent days among yachts and other boats off north Sydney, swimming back to the boats each time officials lured it out to open sea in the hope it would attach to a passing pod of humpback whales.

By Friday morning, the calf was riddled with parasites, starving and injured, and had drifted into very shallow waters, Barnes said. It likely would have died naturally later Friday, but officials hoped to spare it any more suffering, she said.

Some Australians accused wildlife officials of not doing enough to help the calf. A few people designed feeding mechanisms, many gave advice, and some journeyed to Pittwater Inlet just to watch the lonely calf nuzzling up to boats.

Aboriginal whale whisperer Bunna Lawrie tried to soothe the animal Thursday, stroking it while humming a tongue-rolling tune.