Thai Prime Minister Thaksin Shinawatra's latest crackdown against crime is focusing on corruption. In just a few months since the campaign was launched, the police force has come under question, and thousands of unscrupulous officers are being transferred to reserve positions after their corruption was exposed in a massage parlor bribery scandal.

Prime Minister Thaksin, a former police lieutenant-colonel turned telecommunications tycoon, says it is time for errant police officers to "shape up or ship out."

He says his anti "dark influences" campaign has uncovered a strain of corruption in the police force, which hinders efforts to clean up society as a whole.

Somchai Homlaor of the human rights group Asia Forum said police corruption is not new. "I think the corruption in Thai society, actually among the police officers, has very deep roots and [is] very systemic," he said. "To solve the problem of corruption, I think the government should deploy a systematic and holistic approach."

The issue became public when a prominent massage parlor tycoon, Chuwit Kamolvisit, ran in trouble with the law. He said he is angry at the double standard of facing charges when so many police were taking his bribes to leave his businesses alone.

So Mr. Chuwit, nicknamed Thailand's "sex tycoon", began talking. He alleged he has spent $2.5 million in illegal payoffs for police protection in the past 10 years. The prime minister says there is not enough evidence to charge the officers for bribery, but he plans to take the allegations seriously and discipline the suspected men.

Mr. Somchai of Asia Forum said the police have too much power and need better oversight. "The government should reduce the power of the police," he said. "The police should not be the law enforcers for every law, like now, in Thailand."

Prime Minister Thaksin says his aim is to reward honest cops by promotion, and punish crooked cops by demotion. If implemented, thousands of suspect officers will be transferred to reserve or inactive posts.