In a cocaine-fueled act of madness, prime NATALEE HOLLOWAY suspect JORAN VAN DER SLOOT slashed a prison guard’s face with a homemade knife – then attempted to hold the terrified, blood-soaked man hostage.

The ENQUIRER has learned exclusively that the violent drama gripped Peru’s notorious Miguel Castro Castro prison on Jan. 15 after guard Luis Gavancho took Joran’s food tray to his cell.

"Suddenly, for no reason, Joran snatched the tray and hurled it against the wall," a source told The ENQUIRER.

"Gavancho tried to subdue Joran, but the prisoner reached under his mattress and pulled out a small metal bar sharpened to a blade at one end.

"Joran plunged the weapon into Gavancho’s face, slashing a deep cut on his right cheek."

Alerted by Gavancho’s frantic screams, other guards came running – and found Joran holding Gavancho by the neck with one arm and wielding the knife in his free hand.

"In his drugged state, he probably imagined he could hold the guard hostage and maybe escape," said the source.

For the full story it’s in the new ENQUIRER!