FBI agents have left the home of a rural central Indiana man with a collection of thousands of artifacts from around the world.

FBI Special Agent Drew Northern said Wednesday agents didn't confiscate all of the thousands of artifacts in Don C. Miller's sprawling collection, which included such items as shrunken heads, Ming Dynasty jade and a 60-foot anaconda snakeskin.

The FBI team was accompanied by archeologists and anthropologists to inspect the items.

Northern says Miller has improperly possessed some items, but he hasn't been detained or arrested. He says Miller cooperated with investigators since they first went to his home on April 2.

Wendy Osborne, a special agent and spokeswoman from the Indianapolis field office, told FoxNews.com Thursday that the items collected will be analyzed by experts. She did not specify how many items were seized or how long the process of identifying the items will take.

"It may take anywhere from a week to years," she said.

A phone number listed in Miller's name rang busy when The Associated Press called seeking comment.

Northern says the FBI left Miller's Rush County home on Monday. Miller was not arrested or charged, Osborne said.

Fox News' Edmund DeMarche and The Associated Press contributed to this report