The fins, with the flesh still red, lie on the ground as workers with nylon bags keep watch.

Residents and workers in Western, a hub of the dried-fish trade in general, are no strangers to its sights and smells, but this is too much even for them.

'It stinks the whole place out. It affects my mood at work,' a security guard working nearby said.

He described the reek of the partly dried fins as worse than dead fish or rotting meat.

Another guard said: 'When I see so many fins on the ground, I feel that the trade is cruel. They cut off the fins and put the shark back into the sea. That's very bad. I don't eat shark's fin soup anymore.'

Locals say the fins are placed in the street in the morning and taken away when the sun fades.

The practice came to public attention after pictures were circulated on the internet.

'Such sights always make me feel sad, no matter how many times I see them,' said Dr Andy Cornish, director of conservation for WWF Hong Kong, after he was shown a picture. 'Who knows what ocean they were caught from and whether they were poached illegally? We'll probably never know.'

Cornish said it was puzzling to see the fresh fins in Hong Kong as most processing centres were in southern China.

The security guards said the processing had been going on for about two years.

They said the fins were brought in by trucks that usually carried chilled food and workers would watch them during the day then remove them with trolleys or trucks.

A guard said it was worse in summer when the sun was hot and the days were longer. He recalled the time when a 100-metre section of the pavement was covered by fins.

He said many people living and working in the area had complained to government departments including the police, environmental protection and food and environmental hygiene, but little had been done.

Shark fin merchant Chiu Ching-cheung said it was rare to dry fins in such a way here. 'Most wet or frozen shark fins are sent to the mainland for further processing,' he said.

Hong Kong imported more than 9,300 tonnes of dried and frozen shark fins last year. It is estimated that the city accounts for 50 per cent to 80 per cent of the global trade.

Shady business

73 million maximum estimated number of sharks killed each year

9,359 tonnes shark fins imported to Hong Kong in 2009

HK$5,500 maximum price paid in Asia for a kilogram of shark fin

HK$800 maximum price for a bowl of shark?s fin soup

Top exporters of shark fin to Hong Kong are Spain, Singapore and Taiwan

SOURCES: OCEANA (AN INTERNATIONAL MARINE CONSERVATION GROUP), CENSUS AND STATISTICS DEPARTMENT