Human remains have been found inside a car belonging to a missing woman who vanished 42 years ago, solving a mystery that’s haunted the area for decades.

Karen Schepers, 23, who was last seen leaving a night out with coworkers in Elgin, Illinois, a suburb outside of Chicago on April 16, 1983.

The Elgin Police Department announced on Monday that they had located Karen’s Yellow 1980 Toyota Celica buried in Fox River.

Investigators subsequently announced they had recovered skeletal remains from the vehicle which will now undergo DNA testing which could take several weeks.

An image shows the badly degraded car being hoisted out of the water on Tuesday, its yellow paint barely visible under decades of grime.

‘We were pushing against a brick wall for 42 years, and now, it’s starting to give,’ Gary Schepers, one of Karen’s eight siblings, told ABC7.

‘It adds questions more than it answers them. The only search I know of that was done in 1983 was my dad, who was an airline pilot, rented a plane and flew over the area, hoping he could spot her yellow car.’

The vehicle was first located near a boat launch using sonar before a diver located the car and identified the license plate, which matched Schepers’.

‘I wish they looked in the river and found her car 42 years ago,’ Gary added.

Police Chief Ana Lalley said in a statement that the investigation is still open and the recovery process is expected to take some time.

‘As the recovery of the vehicle is made, it is important to stress that this is the beginning of what is still considered an open and active investigation with many questions still to be answered,’ Lalley said in a media update.

‘As we continue to investigate this case, we will remain steadfast in our resolve to provide answers and closure to Karen’s family.’

A renewed interest in the case came last year when Detectives Andrew Houghton and Matthew Vartanian revisited Karen’s disappearance for a podcast titled Somebody Knows Something.

Since the podcast launched, the department has received tips from the community with additional information on Karen’s disappearance.

The saga began on April 16, 1983, when the young woman ventured out for a night on the town with her coworkers.

Karen was last seen at a bar around 1:00 am before she vanished. There were no sightings of her and no clues as to what happened to her.

Very little evidence was uncovered at the time of her disappearance, and suspects who were looked at were quickly ruled out.

Detectives found that Karen had called her fiancé, Terry Schultz, at one point in the night and asked him to come to the bar.

He rejected her offer which resulted in an argument. Terry was investigated as a suspect, but he cooperated with police and passed a lie detector test.

‘With a lot of cases, you have a body that’s been recovered or a vehicle. In this case, there’s neither,’ Detective Vartanian told the Daily Herald.

‘We don’t have a body, we don’t have a car, we don’t have a crime scene.’

The detectives are investigating multiple theories, including that Karen accidentally drove into the river after leaving the bar.

Karen’s credit cards and bank statements were never touched after she vanished, leading investigators to suspect that she didn’t disappear on purpose.

However, the boat launch where the Toyota was located was far from the route she would’ve taken home from the bar.

The detectives researching the case said there was a crescent moon the night Karen disappeared, meaning the road she was driving on was dark.

Elgin has also grown in the past 40 years, so there would’ve been less light pollution on the night of Karen’s disappearance.

Weather data showed that temperatures were below freezing with heavy winds, adding to the theory that Karen could’ve driven off the road accidentally.

The detectives have also begun investigating theories that Karen intentionally harmed herself, wanted to leave Elgin without a trace, or was harmed by someone else.