A paranoid Las Vegas man held his girlfriend captive in her own apartment for more than two weeks, threatened to kill her and forced her to eat lye — because he was convinced she was having him followed, court and jail records show.

Unhinged Benjamin Obadiah Foster, 33, is accused of holding his partner of two years against her will from Sept. 16 until she finally escaped on Oct. 2, according to an arrest report obtained by the Las Vegas Review-Journal.

Foster allegedly used zip ties and duct tape to bind his girlfriend at the wrists and ankles, shaved her head and beat and choked her until she was unconscious.

“Foster also told her that she had cameras hiding all inside the residence that watch him to include the microwave,” according to the arrest report. “Foster then became very physical with her.”

Foster — who investigators said is a trained mixed martial artist — allegedly threatened to kill her with a knife and a small handgun throughout the next two weeks, police said.

At one point, Foster forced the woman to eat a sandwich with lye — a strong chemical typically used for cleaning — that burned her hands and throat, the Las Vegas Sun reports.

Foster also allegedly prevented the woman from using the bathroom and only untied her at night. Still, he held onto her as they slept, she told police.

The woman managed to escape after convincing Foster that the couple needed food and water. He took her with him to a gas station, where she ran away and found help.

Her condition was unclear as of Tuesday, the Review-Journal reports.

Foster, who is set to appear in court on Oct. 21, is being held without bail on charges of first-degree kidnapping, coercion with force, assault with a deadly weapon and domestic battery.

At the time of his arrest, Foster was free on a suspended jail sentence in connection with a 2018 weapons conviction and was awaiting trial in another domestic violence case. It’s unclear if the victim in that incident was also Foster’s girlfriend, the Review-Journal reports.