Fiona Apple -- ADMITTED Drugs Were Hers ... Cops Say

Fiona Apple "freely admitted" the hash and the weed on her tour bus belonged to her when cops discovered the drugs last night ... so says the Hudspeth County Sheriff's Office.

Cops say .... Apple's 2004 tour bus entered the U.S. Border Patrol Checkpoint in Sierra Blanca, TX around 8 PM on Sept. 19 and officers performed a "routine" check of the vehicle.

During the sweep, officers used drug-sniffing dogs ... which detected the presence of narcotics in a blue backpack.

Cops say the backpack contained a glass container with .01 pounds of weed and .01 pounds of hash.

For all of you squares law-abiders unfamiliar with drug weight -- the weed is equivalent to the size of a baseball ... and the hash is equivalent to the size of a golf ball.

Cops say Apple "freely admitted" the drugs were hers and she was placed under arrest.