Updated

Natalee Holloway died from cardiac arrest caused by an accidental drug overdose, a source has told The O'Reilly Factor.

"The Factor has learned from sources we have to protect that Natalee Holloway, the 18-year-old Alabama woman who disappeared two years ago in Aruba, died from cardiac arrest brought on by an overdose of cocaine," Bill O'Reilly said on his Thursday program.

The theory offered by the source, a top law enforcement official, could not be confirmed independently because Holloway's body has not been found.

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Holloway was vacationing with friends on the Caribbean resort island when she disappeared the night of May 30, 2005.

She was seen leaving a bar with Joran van der Sloot and the Kalpoe brothers, Deepak and Satish Kalpoe. The brothers were jailed and later released after a judge ruled there was not enough evidence to hold them.

Van der Sloot, a Dutch citizen who has been attending college in the Netherlands, was also jailed and released. He has said he left Holloway alone on a beach after they kissed and he did not harm her.

At least 10 people have been arrested and released without charges. Hundreds more have been questioned.

The Dutch marines, the local coast guard, the FBI, hundreds of volunteers and others have scoured the island's dunes, beaches and trash dumps for Holloway. Scuba divers and sonar-equipped coast guard ships have also examined the seabed in the unsolved disappearance.