Jackson Doc's Interest in Sleeping Disorders

An interesting turn in the Michael Jackson investigation. Several items were seized at Dr. Conrad Murray's Houston office -- "Pamphlets on Sleep Center."

We're told Jackson may have taken the powerful anesthesia Propofol the day he died because he couldn't sleep. Police believe Dr. Murray may have administered the drug.

The Sleep Center is located near Doctor's Hospital in Houston. Dr. Murray was suspended from Doctor's Hospital -- the administrator tells us he believes the doctor was suspended for not completing medical records in a timely fashion.

As for Dr. Murray's affiliation with the Sleep Center -- a rep from the company hung up when we told them we were TMZ.