BEIJING - China has said a sex change operation should not be an option for criminals seeking to turn over a new leaf.

Individuals with criminal records are ineligible for sex change surgery according to a draft of China's first official guidelines for gender reassignment operations published this week.

Under the new criteria, candidates must live full-time for at least five consecutive years as a member of the opposite sex before surgery and must have one year of psychological therapy, according to the health ministry's website.

Candidates also need a psychologist's recommendation before undergoing the procedure and police must also agree to change the sex on their identity cards before surgery, according to the guidelines posted on Tuesday.

The ministry released the guidelines to solicit opinions, which are due by July 10.

Qiu Renzhong, an ethicist at the Chinese Academy of Social Sciences, told the China Daily that some of the guidelines seemed unreasonable, such as requiring individuals to live as members of the opposite sex before surgery.

'It's hard for them to live and work openly in the gender role they want,' he was quoted as saying.

Qiu also said police should not have a say in the procedure. If someone meets the physical requirements, their identity papers should be changed accordingly, he said.

An estimated 2,000 people have had sex change operations in China and between 100,000 and 400,000 others are considering the surgery, the newspaper reported, adding that no official figures were available.