Updated

Police officers have a message for state lawmakers: Undercover officers need to be able to have sex with prostitutes.

It's a message they're pressing as legislators weigh a bill that would crack down on prostitution. As part of that bill, lawmakers initially did away with an existing exemption allowing officers on duty to have sex with prostitutes during investigations. But after testimony from Honolulu officers, the bill was amended to restore that protection.

The revised proposal has passed the state House and will go before a Senate committee Friday.

Authorities say they need the legal protection to catch lawbreakers in the act, and strict internal controls prohibit misconduct.

"The procedures and conduct of the undercover officers are regulated by department rules, which by nature have to be confidential," Honolulu Police Maj. Jerry Inouye recently told the House Judiciary Committee. "Because if prostitution suspects, pimps and other people are privy to that information, they're going to know exactly how far the undercover officer can and cannot go."

More On This...

But critics, including human trafficking experts and other police, say it's unnecessary and can further victimize sex workers, many of whom have been forced into the trade.

Expert Derek Marsh says the exemption is "antiquated at best" and that police can easily do their jobs without it.

"It doesn't help your case, and at worst you further traumatize someone. And do you think he or she is going to trust a cop again?" asked Marsh, who trains California police in best practices on human trafficking cases and twice has testified to Congress about the issue.

It's not immediately clear whether there are similar provisions in place elsewhere either at the state law or department policy level. But advocates were shocked that Hawaii provides an exemption to prostitution laws for police, suggesting it's an invitation for misconduct.

"Police abuse is part of the life of prostitution," said Melissa Farley, the executive director of the San Francisco-based group Prostitution Research and Education. Farley said that in places without such police protections "women who have escaped prostitution" commonly report being coerced into giving police sexual favors to keep from being arrested or harassed.

The Hawaii bill aims to ratchet up penalties on johns and pimps while leaving the punishment for selling sex as a petty misdemeanor.

Police haven't said how often -- or even if -- they use the exemption. But when they asked legislators to preserve it, they made assurances that internal policies and procedures are in place to prevent officers from taking advantage of it.

Democratic state Rep. Karl Rhoads, chairman of the House Judiciary Committee, said Inouye's testimony convinced him to amend the proposal.

"It's a really murky area," said Rhoads, who represents a district that includes Honolulu's Chinatown, a longstanding epicenter of street prostitution. "I was reluctant to interfere in something that they face all the time. If they think it's necessary to not have it in the statute, this is one area where I did defer to them and say, 'I hope you're not having sex with prostitutes.'"

There have been instances of police being accused of victimizing sex workers across the nation. In Philadelphia, a former officer is on trial facing charges of raping two prostitutes after forcing them at gunpoint to take narcotics. A former West Sacramento, Calif., officer is awaiting sentencing after being found guilty of raping prostitutes in his police cruiser while on patrol. And last year in Massachusetts, a former police officer pleaded guilty to extorting sex from prostitutes he threatened with arrest.

Rhoads, chairman of the House Judiciary Committee, said he knew of no reason to believe Honolulu police are out of line.

"All allegations of misconduct are investigated and the appropriate disciplinary action taken," said Michelle Yu, Honolulu police spokeswoman, in an email.

The Associated Press contributed to this report.