The former head of the Wayne County, MI  Prosecutor Office's drug unit will be suspended with pay Friday and now faces an investigation that could lead to criminal charges for her actions in a 2005 cocaine case.

Prosecutor Kym Worthy, in a prepared statement released late Wednesday afternoon, said she asked the Michigan Prosecuting Attorney's Coordinating Council to find a prosecutor to probe Karen Plants' conduct in the case in which she allowed perjured police and witness testimony. Plants said she did so to protect the identity and safety of a paid informant.

Legal ethics experts and criminal attorneys said the allegations against Plants -- using perjured testimony to win a conviction -- strike at the heart of the criminal justice system.

"I would not bother to ask my class about it, the answer is so obvious," said Len Niehoff, a University of Michigan professor of evidence and legal ethics.

"As a prosecutor, you strike hard, fair blows and let justice be done," said defense lawyer Walter Piszczatowski, a former state and federal prosecutor. "Sometimes you face that choice: Disclose the confidential informant or kiss your case bye-bye. In the end, you have to do the right thing. You don't have people lie."

He said he was especially troubled that the informant stood to collect a percentage of the assets seized from the alleged dealers.

"The guy's got a tremendous motive to lie," Piszczatowski said. "Maybe the testimony's not about trapping criminals. It's about making money, and that's scary."

Worthy asked for the outside prosecutor because it would be a conflict of interest for her office to investigate Plants, a 17-year veteran of her office.

Plants was charged Monday with professional misconduct by the state Attorney Grievance Commission and could lose her law license. The commission also accused Plants of intentionally misleading jurors in her closing arguments. Worthy reassigned Plants from head of the office's Major Drug Unit on Tuesday.

Worthy's request Wednesday for a special prosecutor, which was done pending approval by the attorney general, raises the specter of a top figure in the battle against illegal drugs undergoing a criminal investigation.

Kim Warren Eddie, the council's assistant executive director, said his office should be able to find another prosecutor to pick up the matter within "a couple of days." Reassignments are made many times a year because a potential case involves someone with close professional, personal or family ties to a local prosecutor, Eddie said, adding that the Attorney General's Office could opt to handle the case itself.

Worthy would not comment beyond the prepared statement. Plants' lawyer, Kenneth Mogill, said that "on a personal level it's hard" for his client.

"But it's the right thing to do institutionally," he said. "And just as Kym Worthy is doing the right thing for the institution while this cloud hangs over Karen's head, the evidence is going to show that Karen acted with similar total integrity while prosecuting the case."

The grievance commission, the state Supreme Court's watchdog, charged Plants with professional misconduct Monday for allowing two Inkster cops and their confidential informant to lie under oath during a 2005 cocaine trial.

The episode stems from a March 11, 2005, Downriver drug bust that took 47 kilograms of cocaine off the streets.

During a preliminary examination, two evidentiary hearings and the trial, Plants allowed the officers and a witness to hide his role as the confidential informant, repeatedly denying that they knew one another, preventing defense lawyers from challenging the informant's credibility.

The informant, a paid tipster, was arrested during the bust but was freed without being charged.