(WWJ) - Authorities fear a metro Detroit woman who disappeared last week in northern Michigan could be a victim of foul play.
The Benzie County Sheriff's department wouldn't release any further details about their suspicions surrounding the disappearance of 47-year-old Adrienne Quintal. However, Quintal's boyfriend is now considered a person of interest and has been questioned by police.
"There were some things at the scene that we're holding close to the vest and not releasing, that caused us concern," said Sheriff Ted Schendel. "It's not a simple puzzle to put together."
At this point, no one is in custody and no arrests have been made.
Quintal was last seen downstate as she was headed to Honor, Michigan -- west of Traverse City -- to go to her family's cabin to relax with her boyfriend. She was last heard from early in the morning of Thursday, Oct. 17, when she called a friend in Warren asking for help, officials said.
The friend called the Benzie County Sheriff’s Office; and deputies, assisted by Michigan State police, immediately went to the cabin.
The sheriff's office said investigators found "evidence of possible foul play," but did not find Quintal, who left her vehicle, cell phone and purse behind. A search of the area by a K9 team and aerial drones also didn't turn up any sign of her.
On Saturday, Oct. 19, investigators returned to the cabin to conduct another search of the area, but no new evidence was discovered. Investigators have also been conducting witness interviews in both Benzie County and Southeast Michigan, but so far no tips have led to Quintal.
Schendel said he personally believes that Quintal is no longer in the Benzie County area.
"I say that only because we did an exhaustive search on Saturday on the area around the house," he said. "You know, we don't know what we have. We don't know if someone took their life or anything like that, wandered into the woods and succumbed to hypothermia -- so we did an extensive search in that area using K-9 dogs, cadaver dogs, state police drones from air, CERT (Community Emergency Response Team) people... and after a whole day of searching, we came up negative."
Quintal's son, Nick White, told reporters that his mother did travel to the cabin with her boyfriend, but he returned to their home in Southfield on Tuesday -- two days before she vanished.
"He was up there with her, he came home to drop supplies off, we are working on the condo here," White told Fox 2 News.
Police haven't said much about Quintal's boyfriend and at this point, it's unclear how he might be involved in her disappearance.
As a search for Quintal continues, a cash reward has been increased to $5,000 for tips in the case.
"We're still hopeful that we'll find her alive," said Schendel.
Quintal, who goes by the nickname "Ada," is described as a white female with long brown hair and brown eyes. She is 5'7'' tall and weighs around 125 lbs.
Anyone with information is asked to contact the Benzie County Sheriff's Office at 231-882-4487. Tips can also be submitted to the Michigan State Police Silent Observer at 1-866-774-2345.