The support organization said it plans to distribute the money, stashed in the ceiling of the apartment's bathroom, to victims of the cult's crimes. The cash is believed to be the first asset of the cult discovered after its bankruptcy procedures ended in March.
AUM, known for its deadly sarin nerve gas attacks on Tokyo's subway system in 1995, was declared bankrupt in 1996 and renamed Aleph in 2000.
According to the support group, the cash was discovered in March this year by the manager of the apartment who had been asked by a former AUM leader to check the bathroom in April 2003. The manager was told at the time that an acquaintance of the leader had left his belongings there.
The apartment room had been rented by a female AUM follower between December 1996 and August 2000. The manager eventually found the cash after another occupant had vacated the apartment.
The Tokyo police said there were no traces indicating that the woman follower had actually lived in the apartment and it is possible that it was used as a hideout.
The Metropolitan Police Department, which handed the money to the organization after the expiration of a three-month retention period, is investigating whether the money was used to provide support for wanted AUM fugitives.