Following [article id="1617108"]the searches of the Las Vegas home and medical office[/article] of Michael Jackson's personal physician on Tuesday (July 28), a Drug Enforcement Agency investigator said in a press conference that agents were searching for documents as part of their inquiry into the pop singer's June 25 death.

According to DEA Assistant Special Agent in Charge Mike Flanagan, search warrants on Dr. Conrad Murray's residence and office were executed around 9 a.m. PT, at which point Murray was at home. The doctor was said to be fully aware of the searches.

While the search warrants have been sealed by a judge, Flanagan did speak about the logistics of executing such searches and what materials investigators might target, according to video posted on TMZ.com.

"In a document search warrant, you end up with documents, pieces of paper, hard drives or mirrors of those hard drives, or the computer themselves," Flanagan said. "When you're going through documents, you're going through page by page by page. It's very, very tedious. And everybody in there has the expertise to do that -- what they're looking for. That's very, very time-consuming."

The searches were conducted by members of the Las Vegas and Los Angeles DEA and both cities' police departments. "There's quite a few people up there," Flanagan said.

Murray has not been detained by authorities and was said to still be at his home following the searches.

When asked if investigators were looking for specific drugs, such as Propofol, a powerful sedative [article id="1617069"]Murray reportedly administered to Jackson[/article] and which might have caused his death, Flanagan said, "No, not that I know of."