The probability is great enough to allow covert investigation, and it might be best if you accompanied a Central Four observer.

The discoveries followed a lengthy, covert criminal investigation by South Australian Police.

Several more arrests are expected as part of covert investigations.

Joe was murdered by these dirty cops when his covert investigation into their corruption was getting too close.

"We have not been able to do a covert investigation in more than a year," Mr. Wyden complained.

You know, Em, I don't mind running a covert investigation, but it is hurting my success rate.

Internal Affairs launched a covert investigation of the Fish phenomenon following a frantic phone call from a north side district commander.

You simply couldn't run a covert investigation for very long, even under the best of circumstances.

He'd be a Security hero-his mind raced ahead, already plotting the next move in his covert investigation.

"People don't bother me that much," he says, studiously ignoring the covert investigation still being conducted around him.