BEIJING - On a tour in Beijing, you may find yourself in a drugstore, being diagnosed with some illnesses previously unknown to you and buying expensive traditional Chinese medicines.

Foreigners accuse a retail store of Beijing-based Tongrentang Co., Ltd., the largest producer of traditional Chinese medicine (TCM) in China, of tricking them into buying unnecessary medicine from suspicious sources.

American tourist Wei De, who gave only his Chinese name, booked a one-day tour with Xiandai Tourism Agency, a subsidiary of China Travel Service at Wangfujing Grand Hotel in downtown Beijing on May 14.

"The tour schedule was to visit the tomb of the Emperor Yongle in the morning and the Great Wall in the afternoon, but I was taken to Tongrentang Nanchengtianhui drugstore in Changping district at midday," said Wei De.

At the drugstore, Wei was introduced to a "professor" in a doctor's uniform. After the "professor" felt Wei's pulse, Wei was told that his kidney was quite weak, so he paid 780 yuan ($120) for a packet of medicine.

"I found that most tourists were diagnosed with similar problems. The 'professor' said we all had something wrong with our kidney," said Wei.

Tongrentang, a household name in China, was founded in 1669 and was once designated to provide medicines to the family of the emperor.

The receipt issued by the store shows that the payment was made to the outpatient department of Beijing University of Chinese Medicine. Some packages of medicine read that the medicine producer was Beijing Hanci Chinese Medicine Hospital, "located in the Nanchengtianhui drugstore."

Many foreign visitors felt cheated since the medicine they received was not produced by the renowned Tongrentang.

"This is my first trip to China and I was swindled at this pharmacy in March. It is horrible that they hijacked the famous brand to deceive people," said Alex Cleveland from Sweden.

Jiang Xiaodong, head of Tongrentang's publicity department, said that, "Nanchengtianhui drugstore is one of Tongrentang's franchised outlet," but denied the store had sold overpriced medicine from unknown sources.

"And if customers bought the medicine from Hanci hospital, then this has nothing to do with us," said Jiang.

As for whether the tourists were over-charged and what the medicine was composed of, Beijing Drug Administration will begin an investigation into Nanchengtianhui drugstore Thursday afternoon.

Foreigners' complaints often fall on deaf ears because of language barriers and some tourism agencies and hotels are in cahoots with the sellers, said a manager of a Beijing-based tourism company on condition of anonymity.

Spanish daily newspaper ABC's corespondent Pablo had a similar experience and complained to Beijing Tourism Bureau, his travel agency and the hotel. But all he got was a 700-yuan compensation from the hotel. A dozen compliant emails were never replied to, he said.

"Having been living in China for six years, I would not let my one-time bad experience at the drugstore tarnish my overall impression of China. But for those who had been to China just once, they would surely be disappointed," said Pablo.