PRINCETON - (AP) - Police say the white, powdery substancefound in a letter delivered Monday to a Princeton Township businesswas just powdered sugar.

But it's not clear who sent the letter or why. And authoritiessay the FBI and Homeland Security officials may join theinvestigation.

Princeton Township Police Sgt. Michael Cifelli says no injurieswere reported in the incident.

In an apparently unrelated incident, a hazardous materials teamwas dispatched Monday afternoon to University Medical Center atPrinceton to investigate another suspicious material report. Butfurther details were not disclosed.

In 2001, five people were killed when Anthrax-laced letters weremailed from a mailbox in Princeton to lawmakers and newsorganizations. Prosecutors were preparing to indict Army scientistBruce Ivins for the attacks when he killed himself in 2008.