A report released by Greenpeace showed five out of 10 samples of strawberries and tangerines imported from China were contaminated by highly toxic chemicals such as methamidophos and DDT, banned pesticides.

One tangerine sample contained 13 kinds of pesticide, the study found, warning that the chemicals were poisonous to the nervous system and can cause long-term health problems.

The report follows revelations by the pressure group last April of toxins in vegetables sold in local supermarkets.

Greenpeace accused the government of doing little to improve food safety in the territory since then.

"We have been raising time and time again the urgency of the problem since last year," said Apple Chow, Greenpeace assistant campaigner.

"Regrettably the government simply turns a blind eye to it. We believe that the government has the responsibility and the need to enact a law as soon as possible to monitor the safety of imported food," Chow added.

The group staged a protest outside government offices Tuesday to press their point.

Greenpeace members dumped the contaminated produce at the door of the Centre for Food Safety, condemning what they called official incompetence in preventing the import of toxic produce.

"We believe that the problem is getting very serious," Chow said in front of a large yellow banner that read "Stop Toxic Fruits and Veggies".

Chow demanded the government set a timetable for food safety legislation and also set safety limits for the amounts of residual pesticides found in foods.

Further, she called on authorities to draw up laws to monitor food imports by setting up a licensing system for suppliers and reinforcing mandatory inspections at the border.

Greenpeace also cast doubt on the accuracy of a government food test last year which cleared 350 fresh fruit samples of any contamination.

The government food and environmental hygiene department declined to comment on the report. It only said it often takes tests on food samples to ensure food safety and would continue to do so.

The findings are the latest in a line of scandals surrounding food imported from China, on which Hong Kong relies for the majority of its fresh produce.

Imports of many species of farmed fish, eels and eggs from mainland China were banned last year after cancer-causing chemicals were found in some samples.

There have been other recent scares over pork from China as well as poultry imports amid growing bird flu outbreaks in the region and elsewhere.