Sydney  - A 37-year-old swimmer lost "great big chunks" of his leg when he was attacked Saturday by a 4-metre shark at a popular beach on Australia's west coast.

Police said the man was just 80 metres off Albany beach and amongst dozens of other swimmers.

He is now in a stable condition in Albany hospital.

Fellow swimmer Jo Lucas told the West Australian newspaper she was shocked that a shark would come so close to shore.

"I just saw someone thrashing in the water and saying 'Help me, Help me," Lucas said. "I grabbed him and swam back into shore."

Lucas said there were "great big chunks missing" from his leg but that he remained calm and didn't appear to have lost a lot of blood. (dpa)