A missing woman has been found chained by her neck, gagged and tied to a mattress at her ex-boyfriend’s home after allegedly being held captive for five days.

Emiliane Tamara Nunes Carvalho was rescued by police from a property in Brazil on Friday after her family reported her missing five days earlier.

Police allege that the 24-year-old was abducted by former partner Ailton Rodrigues de Souza after she left home for a medical appointment on August 17.

Officers stormed the rundown property in Aguas Lindas de Goias after tracing a vehicle bought by Mr de Souza to the area.

Shocking video released by police shows officers cutting through a lock before forcing their way into the house.

They then kick down a door at the back of the property and find Ms Carvalho lying on a mattress, bound with ropes and chains.

She was reportedly restrained by her hands, feet and neck, with handcuffs also used to keep her captive.

Police said that she was struggling to breathe and had a mask and gag over her face, which they allege was used to prevent neighbours from hearing her screams.

Ms Carvalho was taken to hospital after the rescue and has since been discharged.

In a series of emotional videos posted online after returning home, she showed injuries to her face and said that she was still taking medication and suffering problems with her eyesight.

She also made a horrifying allegation about the abuse she claims she suffered during her captivity, saying her ex forced cloths containing acid into her mouth.

“I am all burned inside because he was putting cloths with acid inside me,” she said in the video.

Police allege Mr de Souza drugged Ms Carvalho before taking her to the property and later confessed to doing so.

Officers seized a 9mm pistol, sedatives and items allegedly used to restrain her during a raid on the house.

Police also became suspicious after Mr de Souza’s family reported him missing.

Authorities allege he had attempted to create a false trail by disappearing himself while Ms Carvalho was being held captive.

Mr de Souza was arrested on Friday, the same day Ms Carvalho was rescued.

A court later ordered that he remain in preventive detention after a custody hearing, with the judge citing alleged repeated threats, physical coercion and restriction of Ms Carvalho’s freedom.

The case has taken another disturbing turn after police reportedly found a handwritten letter inside the property addressed to Ms Carvalho’s family.

The letter appeared to be a farewell message and included a request for her family not to contact police.

Authorities have not confirmed who wrote the letter or whether it was written freely or under coercion.

Ms Carvalho has said that she and Mr de Souza separated in December, despite claims he refused to accept the end of their relationship.

The investigation is ongoing.