The FBI seized thousands of artifacts from a 91-year-old man’s rural home in Rush County, Ind. Donald Miller had a private collection with artifacts that represented Native American, Russian and other cultures.

The FBI set up tents and brought a command vehicle to Miller’s home in Waldron, 35 miles southeast of Indianapolis, reports The Indianapolis Star. Miller has not been charged with a crime.

During a news conference, FBI special agent Robert A. Jones declined to go into any details in the raid and would not even reveal what started an investigation into Miller. He only said that they received information about Miller’s collection and their arts crime team decided to act.

Jones also refused to say anything about specific items in the collection, only noting that they came from China, Russia, Peru, Haiti, Australia and New Guinea. There are also Native American objects in the collection.

While Jones noted that the objects weren’t kept in museum-quality storage, he said that Miller did his best to care for them. The next step in the investigation will be identifying what each object is.

According to ABC affiliate RTV6, Miller is said to be cooperating with the investigation.

NPR adds that the Rushville Republican did a story on Miller, who talked about working on the atomic bomb in 1944 and 1945.