The menacing ghost of “Underground Railroad” conductor Harriet Tubman has been roaming the halls of the Kremlin and frightening the normally unflappable President, an aide to Vladimir Putin revealed Monday.

According to the source, the ghost appeared shortly after the release of the President’s judo textbook last year and has been wandering the Kremlin grounds ever since.

“The ghost has a thing about him (Putin),” he said. “It floats behind him when he walks and when he turns around, it mimics judo moves in the air. Sometimes it appears to be challenging the President to a fight.”

Putin’s first response to the ghost was to try to have it arrested, but Kremlin guards rushed to the scene were shocked to discover that their hands passed cleanly through the ex-slave’s vaprous body when they tried to apprehend her. The ghost then disappeared through the door of a nearby rest room, frustrating its pursuers.

The ghost was identified when Kremlin security footage of the haunting was analyzed by highly-trained experts at the Russian Federal Security Bureau, or FSB. In several frames, clear images of the ghost’s world-weary face were visible as it maneuvered into judo positions behind the president.

“We compared the image to photos in our database, and what we came up with was Harriet Tubman,” the FSB analyst said.

Curiously, the ghost appeared to be wearing exactly the same dress that Tubman wore in the one surviving photograph of the famous slave-liberator, taken in 1880.

Tubman, born Araminta Ross, was originally a slave from Dorchester county in Maryland. After her marriage to free black John Tubman, she escaped to the north.

She subsequently helped more than 300 slaves escape along the famous “Underground Railroad”, but never visited Russia.

The story about Tubman’s ghost surfaced when the Duma called special hearings to inquire into the nature of a mysterious Kremlin budget expenditure which was later revealed to be a top-secret operation to capture the apparition.

Sources say that in one capture attempt last fall, Kremlin operatives tried to catch the ghost in a net as it chased a fleeing Putin down a corridor in the direction of the Georgevsky Hall. The net was raised as Putin entered the famous reception hall, but the ghost foiled the capture by flying through the snare and continuing the chase the beleaguered president around the room.

A portrait of Alexander III was damaged as Putin flailed his hands over his head in an attempt to drive the ghost away.

American paranormal experts are both mystified and intrigued by the ghost’s choice of Putin as a haunting subject.

“The Kremlin is not the place where we would have expected Harriet Tubman’s ghost to appear,” said occultist Parker Jarvis, author of The Haunting of Dennis Quaid. “But ghosts have their reasons.”