A raid at an angling shop south of Johannesburg saved 2,000 frogs from an early death at the end of a fishing hook, an animal protection group said today.

The frogs were spared after police officers were called on to back up welfare inspectors at Solly's Angler's Supplies in the town of Vereeniging after the shop manager refused them entry.

"The conditions the animals were kept in were horrific," Jaco Pieterse, an inspector with the National Council of Societies for the Prevention of Cruelty to Animals (NSPCA), told AFP.

"The water was rotten, the frogs were on top of each other, with those at the bottom of the containers suffocating," he said.

The frogs were released back into the wild after the raid.

Trade in live frogs is booming due to the Christmas holiday season, according to Pieterse.

"People use frogs as live bait all year long, but during the holidays more people go camping and fishing and more people want to use live bait during the festive season," he said.

Animal welfare charges are being considered against the shop's owners for keeping the frogs in poor conditions but more serious charges cannot be brought because they had not yet been used by anglers to lure fish.

"The problem is we have to catch them doing it," Pieterse said, urging anglers to use non-live bait.