Fischer, 61, was recently placed in custody at the Tokyo Immigration Bureau's Narita office as he tried to leave Japan for the Philippines.
Japanese immigration officials plan to extradite Fischer to the United States. Japan Today said he was held on charges of possessing an illegal passport.
"We cannot reveal it because it involves his personal information," an official said.
The Chicago-born Fischer became the U.S. chess champion at age 14 and won the world title when he was 29 years old. He retired from the world chess scene but broke his retirement in 1992 to pay in a tournament in Yugoslavia, which at the time was under sanctions.
The date of Fischer's detention was not immediately available.