State Police called the man a “person of interest” and asked the public for help identifying him “so that they can question him”.

The man pictured was “seen in Devil’s Den State Park on Saturday,” police said in a statement.

The call for information comes after Clinton David Brink, 43, and Cristen Amanda Brink, 41, were found dead on a walking trail in Devil’s Den State Park in north-west Arkansas over the weekend.

Investigators did not say how the couple was killed, but noted their deaths were being investigated as a double homicide.

The suspect “likely sustained an injury while attacking the couple,” Arkansas state police said, without elaborating.

“Washington County received a call from the visitor centre,” said police radio audio captured by Broadcastify.com.

“Two children are there. They advised that their parents were assaulted. One was possibly stabbed. The parents are missing.”

Their daughters, ages 7 and 9, were unharmed and are now safe with family members, police said.

State police are imploring anyone who was at Devil’s Den State Park on July 26 to review any video or photo footage they may have for images of the person of interest.

Police have also asked local residents to check their security or game camera footage for a possible sighting of the vehicle the suspect was driving.

“Do not post evidence online: Instead, preserve the original files and submit information to ASP,” a release on Tuesday instructed.

The Brinks had recently moved from another state to Prairie Grove, a small town in northwest Arkansas near the Oklahoma border, according to police.

Their family released a statement Monday asking for privacy.

“They ask that if anyone has any information at all that will help the investigation, to please contact the proper authorities immediately. Clinton and Cristen died heroes, protecting their little girls and they deserve justice,” the statement read. “They will forever live on in all of our hearts.”

The 1000-hectare Devil’s Den State Park is known for its rugged natural scenery filled with waterfalls, caves and rock formations, according to Arkansas State Parks. The killings happened in an area of the park with thick vegetation and “no cellphone service,” police said.

Audio from first responders indicates the couple’s bodies were found on the Devil’s Den Trail, a 2.4km loop with “moderate” difficulty, according to a guide from Arkansas State Parks. It’s one of 11 trails inside the park and its trailhead is close to the park’s visitor centre.

“All trails are closed until further notice,” a statement on the park’s website says.

While searching the trail, first responders could hear yells for help, scanner audio indicates. It’s not clear from the audio who was yelling.

“I hear yells calling for help. We’re walking down,” a first responder can be heard saying.

It’s also unclear how long it took for authorities to locate the bodies of the couple.

“Try to relay to the office that we found the victims down here,” a first responder can be heard saying. “They’re on the lower Devil’s Den Trail. … I think I see you right there. I’ve got two bodies down here.”

Arkansas State Police said they were notified around 2:40 p.m. of the deaths and asked for the public’s help in identifying the suspect.

Police earlier described the suspect as a medium-build white male, last seen wearing a shirt with rolled-up long sleeves, dark pants, a dark baseball cap, fingerless gloves and sunglasses and carrying a black backpack. He was seen “driving toward a park exit in a black, four-door sedan,” possibly a Mazda, with a licence plate covered by electrical or duct tape, authorities said.

The vehicle may have travelled on State Highway 170 or State Highway 220 near the park, police said.

Investigators have received “numerous calls from the public with possible tips,” state police said on Monday.

Authorities earlier urged Saturday’s park visitors to review their photos and videos for images of the suspect. Investigators also asked residents in the area surrounding the park to check security and game camera recordings for possible leads.

Officials warned against sharing any footage on social media, cautioning that doing so “may inadvertently jeopardise the investigation”.

The area where the killings happened has been cordoned off as the investigation is ongoing.

Arkansas Governor Sarah Huckabee Sanders called the killings “horrific” and said the state was “in close contact with State Police and the Department of Parks, Heritage and Tourism as they work to apprehend the suspect.”

Law enforcement would be increased at state parks across Arkansas in response to the killings, said Shea Lewis, secretary of the Arkansas Department of Parks, Heritage and Tourism.