Private agencies that help foreigners with their visa problems should be given clearer parameters and fall under the supervision of the government, immigration experts said.

The new regulation that is intended to simplify immigration for both foreigners and Chinese allows "special service institutes" to be hired by a foreigner to help with documentation involving visas or residential permits.

But Liu Guofu, an immigration law professor at the Beijing Institute of Technology, said more specific rules are needed to define what activities are legal for these agencies. He suggested that the public security and foreign affairs ministries, as well as related government departments, work out a regulation on the management of entry-and-exit agents.

"By giving these agents a legitimate status, it can keep foreigners away from redundant paperwork and improve the efficiency of public security authorities and foreign affairs authorities," Liu said.

He said that there are already many underground agents helping foreigners and that the best way to manage them is to bring them under government supervision.

A US citizen questioned the actions of a visa agency he recently hired.

Two weeks before his F business visa expired, he sought the help of an exit-and-entry agency. After five weeks of searching, e-mailing, calling and meeting up with agencies, he found a visa agency and was charged 6,756 yuan ($1,100). He said it was the cheapest agency he could find. The agency took care of his visa extension in 10 days without requiring him to provide any certificates, he said.

"I don't know if it was legal or illegal," he said. "Every foreigner in China has to face the visa issue. Complicated procedures, plus the bad translation of the regulation, left us no choice but to find overpriced agencies taking care of all these."

The lack of specific rights and duties for these agencies results in a massive legal gray area, said Qi Lixin, chairman of the Beijing Entry and Exit Service Association.

"These agencies only process documents," he said.

Qi said the new regulation is also unclear about the actions an agency should take when a foreigner provides fake documents.