Image copyright Montgomery County Sheriff Image caption The partially clad woman, wearing what appeared to be wrist restraints, was caught on a security camera

A mystery woman who was caught on a surveillance camera wearing what looked like broken wrist restraints has been found safe, police in Texas say.

A search was launched after the barefooted woman was filmed ringing a doorbell in the middle of the night.

Police in Montgomery County said the woman, aged 32, was now with family and would not be identified as she was a victim of domestic violence.

They said her 49-year-old boyfriend had been found dead in a suspected suicide.

Lt Scott Spencer of Montgomery County Sheriff's Office said the boyfriend, identified as Dennis Ray Collins, allegedly used restraints on the woman before she was able to break free to seek help.

Investigators say they have yet to determine how long she was restrained before she was seen ringing doorbells in the community of Sunrise Ranch, 60 miles (95km) north of Houston, in the early hours of last Friday.

When she was unable to get help she returned to the residence, according to Lt Spencer.

Collins' ex-wife told police she received concerning text messages from him, and that she believed his girlfriend was the woman in the video, Lt Spencer told a news conference on Thursday.

Deputies found Collins' body on Wednesday morning at a house and said he had died from a single gunshot wound.

Image copyright Montgomery County Sheriff's Office

Lt Spencer added that the boyfriend had left a suicide note which had helped authorities to identify the woman in the video and explain what happened.

Police were then able to contact the woman through members of her family, according to Lt Spencer.

Investigators met the woman on Wednesday and confirmed her identity. She provided details that "only the female in the video would have known", he added.

She described evidence at the scene as well as the restraints seen in the video as ones "commonly used in private intimate encounters".

The alarm was raised after a resident at Sunrise Ranch was woken by her doorbell being rung at around 03:20 local time on Friday. By the time the householder answered, the caller had gone but the resident reviewed the security footage and sent it to police.

The same barefoot woman rang the doorbells of other homes in the area, but vanished in each case before anyone answered.

The sheriff's office said at the time that the woman did not match anyone from missing person reports.

Authorities conducted a door-to-door search of homes and businesses and circulated images of the woman.