A Kalamazoo Department of Public Safety sergeant who department reports said received oral sex from a suspect during a 2003 undercover prostitution investigation broke no law, according to Kalamazoo's Public Safety chief and the county's chief prosecutor.

But even if such sexual conduct by police officers is allowed under law, other law enforcement officials say they would never authorize it.

Kalamazoo Public Safety Chief Dan Weston says he can recall no instance in which his department has OK'd sexual contact during a vice investigation, even though that's allowed under a 29-year department policy.

Weston and Kalamazoo County Prosecutor Jeff Fink said a 1931 Michigan law prohibits solicitation -- the offer of money for sex. But a 1969 amendment exempts police officers from criminal prosecution if they participate in offering money for sex during an official investigation.

Michigan State Police First Lt. Greg Zarotney said state statutes only require law enforcement officers to show a person has agreed to accept money in exchange for sexual activity to make their bust.

``The fact that they've engaged in the transaction is the crime we're looking for,'' said Zarotney, assigned to the MSP's Lansing executive headquarters. ``There's no need to go extra steps to prove the offense.''

Zarotney said sexual contact by a trooper during a prostitution investigation would be considered ``conduct unbecoming an officer'' and could bring discipline ranging from a ``verbal reprimand to termination.''

Sex between consenting adults is not illegal, Fink said. So an officer participating in a sex act during the course of an undercover prostitution sting would have committed no crime, according to Fink.

``It's certainly not new or unheard of in vice investigations for (sexual) contact to take place in the furtherance of an investigation,'' Weston said. ``We have departmental policies that call for the strict supervision of drug and vice investigations. But it would not violate any law.''

Kalamazoo County Sheriff Michael Anderson said the law may allow officers to engage in such sexual conduct, but he would never authorize a deputy to go beyond offering money to a suspected prostitute to make a case.