Accused killer JORAN VAN DER SLOOT has begun a jailhouse romance with a mystery woman who’s been allowed to visit him in his cell, The ENQUIRER has learned exclusively.

The slim, 30-something blonde calls on Dutch-born Joran twice a week at the grim Miguel Castro Castro prison in Lima, Peru.

“She’s a white foreigner with short blonde hair who speaks English and Spanish fluently. Guards as well as prisoners refer to her as ‘the Dutchman’s gringa,’” revealed a source close to the case.

Joran has called the woman “my girlfriend” in conversations with Hugo Trujillo Ospina aka “The Clown,” the Colombian assassin who shares his cell block. However, it is unlikely that Joran has been able to get very intimate with the woman inside the 2,300-inmate prison because he is never left unguarded.

She began visiting van der Sloot, 23, on June 20 — 17 days after he was arrested for the brutal murder of Stephany Flores, the 21-year-old daughter of a wealthy businessman.

According to prison sources, the unlikely romance blossomed after van der Sloot’s mother began paying the woman $100 a month to take him food, money and clothing, and report on his condition.

During one recent 30-minute visit, guards’ records show that she brought him five cans of tuna and another five cans of beans with bacon, plus bread, jam and water.