Mr Yang was once China's second-richest man

Mr Yang, until recently listed as China's second-richest man, could face a life sentence.

He is defending a range of charges, including the falsification of financial documents to enable him to list his orchid-exporting company, Euro-Asia, in Hong Kong in 2001.

He is also accused of illegally using agricultural land and bribing officials.

The long-awaited trial is the third high-profile Chinese corruption case in recent weeks, following the detention of Shanghai property magnate Zhou Zhengyi and Hong Kong banker Liu Jinbao.

Pyongyang's plan

Mr Yang was detained in October, just days after North Korea named him head of a new free-trade enclave on the Chinese border.

The project was part of a general economic thaw in Stalinist North Korea, which has toyed with reform in recent years.

The intention was to wall off the city of Sinuiju from the rest of North Korea, remove its population, and move in skilled workers.

The plan has, however, failed to take off.

Some have alleged that Mr Yang was arrested, because the Chinese authorities were not consulted by Pyongyang over his appointment.

Party politics

Mr Yang has been the first prominent businessman to fall foul of the law since the Chinese Communist Party officially became tycoon-friendly last November.

The party is keen to enrol a number of rich capitalists to its ranks, but is simultaneously stepping up its attacks on corporate sleaze.

A succession of business scandals has underlined the close links between officials and businessmen, many of whom depend on government patronage for their success.