Dutch teenager Joran van der Sloot is terrified he and his family will be murdered if he confesses all he knows about the disappearance of Natalee Holloway.

The National Enquirer can reveal that police on Aruba are investigating this theory, which centers on whether narcotics dealers supplied Joran with the drug ecstasy, helped him get rid of Natalee’s body — and told him he’d vanish forever if he didn’t keep his mouth shut.

“Joran’s statements have changed many times because he does not want police to find out who helped dispose of Natalee’s body,” said a source close to the case. “Police believe that people involved in getting rid of the body have threatened to murder Joran and his family if he ever names them.”

Natalee, 18, vanished May 30 while on a high school graduation trip to Aruba with classmates from Alabama’s Mountain Brook High School.

She was last seen leaving a nightclub and getting into a car with Joran, 17, and his friends, Deepak Kalpoe, 21, and his brother Satish, 18.

During their investigations, police have arrested two security guards, Joran, the Kalpoe brothers, a party boat disc jockey and Joran’s father Paulus. All were released except Joran — and he remains the prime suspect.

Joran maintains his innocence but has changed his story. First he said he dropped a drunk Natalee off at the Holiday Inn where she was staying after a makeout session with her in the back of the Kalpoes’ car. Later he said the Kalpoe brothers dropped him and Natalee off on a beach near the island’s Marriott hotel and he left her there alone.

As The National Enquirer reported last week, police theorize that Natalee died accidentally, possibly drowning after she fell and hit her head in a drug-induced stupor. Police also believe Joran confessed to his father that Natalee had taken ecstasy and when she died, Joran panicked and decided to get rid of the body. But he needed help — and knew where to find it.

“Joran is believed to be friends with a known ecstasy dealer in Aruba and police think that’s where he got the drug,” said the source.

“When Natalee died, Joran got in touch with the dealer. The theory is that the dealer had an incentive to dispose of her body so that police wouldn’t trace the drugs back to him. But the dealer made it clear to Joran that if he talked he’d disappear too.”

On a similar note, police are investigating whether Paulus, a former justice department official, helped his son get rid of Natalee’s body by contacting shady characters he knows.

“The police are looking into Paulus van der Sloot’s finances and whether he might be connected to mobsters that may have ties to Aruba’s casino business,” said the source. “Paulus is a known high-stakes poker player.”

The National Enquirer has also uncovered details of Joran’s activities in the early hours of May 30.

“Police discovered Joran used his cell phone to send an instant message marked ‘URGENT!’ to Deepak Kalpoe at approximately 2.45 am,” said the source. “The instant message essentially told Deepak that Joran was walking home from the beach. He said he had ‘left the girl behind.’

“At approximately 3:30 am, Joran sent the first of a series of other instant messages from his home computer to Deepak indicating he needed to talk to him about something important. After examining Joran’s cell phone and computer, police discovered that someone tried to manipulate the clocks and calendars inside the devices so it would look like the messages were sent at different times.

“Police think it’s suspicious that Joran’s instant message to Deepak was marked urgent — they believe it was critical for Joran to reach him to concoct a phony story about what happened to Natalee.”