DALLAS -- Authorities believe paid informants to North Texas law officers may have purchased quantities of white pool hall chalk to be planted on innocent people.

Those reports are now part of a federal investigation.

Those targeted with the chalk were later arrested for dealing drugs.

Inquiries into the series of drug busts have resulted in the dismissal of more than 60 felony drug charges, an FBI review and suspension of two undercover detectives.

Cooperation of Reyes Roberto Rodriguez, one of several informants who had acted as a subcontractor to the Police Department's primary informant, had helped the FBI begin answering questions about how dozens of people were falsely accused of drug dealing by Dallas police.

Chalk cones were confiscated by FBI agents from the home of one of the jailed informants. Agents also collected receipts for large quantities of the substance from a supply house.