Fears about food imports have mounted after news last month that 10 people had fallen ill from eating dumplings made in a northern Chinese factory. The dumplings were contaminated with pesticide.

Japanese media have since reported on other Chinese-made foods laced with pesticide, although there were no reports of any additional people becoming ill.

Chinese State Councillor Tang Jiaxuan, who arrived on Wednesday for a five-day visit to prepare for Mr Hu's visit, told a reception that he hoped for progress in a joint investigation into the contaminated dumplings, Kyodo news agency said.

'I express my sincere sympathy to those affected in the incident, and I hope that we will get to the truth as soon as possible through close cooperation between the Chinese and Japanese sides,' Mr Tang was quoted as saying by Kyodo.

China has said the food scare, which has dominated news programmes in Japan, would not affect Mr Hu's trip.

He is expected to make the first visit to Japan by a Chinese president in a decade, probably in April.

Relations between the neighbours have been strained by a range of issues, mostly dating back to Japan's occupation of parts of China last century, but they have improved in recent years along with flourishing business ties.

Japanese officials have hinted the dumplings might have been tainted by activists against warming bilateral relations, but a senior Chinese official said last week there was almost no chance the dumplings were contaminated in China on purpose.

But Chinese Foreign Ministry spokesman Liu Jianchao said it was too early to draw any conclusions.

'Making such a judgement, such speculation is unscientific.

There still needs to be an earnest, scientific and comprehensive investigation,' he told reporters in Beijing.

A team of Chinese police officers arrived in Tokyo on Wednesday for talks with their Japanese counterparts.

China has been at pains to reassure the world that its food is safe after a series of health scares drew attention to lax oversight and a willingness among manufacturers to flout standards with a view to maximising profits.

Beijing, in particular, has emphasised its efforts to ensure food safety ahead of this year's Olympic Games.

Meat supplies have come under scrutiny over fears that antibiotics and growth stimulants commonly used by breeders to boost yields could cause positive doping tests.

Beijing expressed regret on Thursday at reports the US Olympic team would bring its own meat for the Games. Chinese officials said the government could guarantee safe supplies. -- REUTERS