The FBI and the Los Angeles Police Department are investigating the suspicious letter addressed to Bristol Palin at "Dancing with the Stars," TMZ reports.

According to the report, they are looking into the possibility that the package, which had a white powdery substance, could be connected to a previous incident with Palin in 2010.

"Law enforcement sources tell us both agencies are taking the package's threat very seriously," reports TMZ.

In 2010, a similar suspicious letter was sent to CBS with a threat addressed to Bristol.

An unusual package was delivered to the CBS lot in Hollywood that contained suspicious white powder on Wednesday.

Security was alerted and emergency workers were brought to the lot to take care of the package. The white powder has been sent to a lab, but so far there is no reason to suspect that it's anything harmful.

This was an apparent threat directed to the executives of the hit show for having Bristol Palin on the cast, according to a report by TMZ.com . A note was attached that stated more packages of the same nature would be sent to the studio lot if Palin, the daughter of former vice presidential candidate Sara Palin, wasn't removed from the show.

Palin has been the target of past threats for her appearance on the show. In 2010, a suspicious letter was sent to the "Dancing With the Stars" studio that had Palin's name on it with death threats. That time it was talcum powder that was put in the fan letter, but that didn't stop an FBI investigation.

Tags: dancing with the stars all stars