Earlier this week, we told you about an armored truck that was robbed of nearly $5 million worth of gold bars on a North Carolina highway. 

Many commenters on social media immediately posited that the heist was an inside job, and now police reportedly suspect the same. 

They say the three armed robbers arrived almost immediately after the truck drivers made an unscheduled stop on a dark stretch of highway.

The crew is said to have left their weapons behind in the truck when they got out, which is against their employer's security rules. 

They said they got out of the truck because of gas fumes and one of them felt sick.

The sheriff declined to comment Wednesday after one investigator said it could have been an "inside job."

More from AP:

On Wednesday, authorities released search warrants for the truck and the drivers' cellphones filed the day after the heist in which detectives wrote of their suspicions.

"The fact that the truck was robbed immediately upon pulling over at an unannounced stop is suspicious in and of itself," the warrants state, adding that the truck had no external markings betraying the cargo. The warrant said the suspects tried to steal the truck but could not get it started, indicating they did not know how to operate a commercial truck.

Woodard said the guards were still considered victims, not suspects, but that all possibilities were being investigated.

Asked to elaborate on the suspicions mentioned in the warrants, the sheriff said they were written in a hurry before the victims, who spoke little English, could be thoroughly interviewed in Spanish.

The strange scene unfolded around dusk Sunday in a rural area about 50 miles east of Raleigh.

Earlier in the day, the guards had stopped for gas in Dillon, South Carolina, near the North Carolina line. As they kept driving, one of them started to feel sick and said he smelled gas, Woodard said. A warrant says they pulled over so the man could vomit.

As soon as the guards stopped on the shoulder, three robbers drove up in a cargo van and confronted them at gunpoint, yelling "Policia!" and ordering the crew to lie on the ground.

The guards got out of the tractor-trailer without their guns, according to the sheriff, who said it was a company security violation to leave the truck without their weapons.

The robbers tied their hands behind their backs and marched them into nearby woods, authorities said. Woodard said the robbers cut a padlock, but there were no other security measures to stop them.

He said that after deputies arrived, a mechanic found no problems with the truck.

The heist happened hours after the truck left Miami for a town south of Boston.

Neither guard was injured, according to their employer, Miami-based Transvalue Inc., which specializes in transporting cash, precious metals, gems and jewelry. A Transvalue spokeswoman said she would seek comment from company's executives about the details in the warrants.

The company has offered a $50,000 reward for information leading to an arrest. The company says its shipments are insured for up to $100 million.

One warrant says the owner of the cargo was Republic Metals Corp. of Opa-locka, Florida. An attorney for the company did not return a telephone call seeking comment late Wednesday.

After the thieves escaped with the gold, the guards were left stranded along Interstate 95 until they drew the attention of startled motorists. Several called 911 to report seeing uniformed men running into the highway with their hands bound, motioning for help.

"They've got their hands zip-tied behind their backs, and they're out in the road to try to flag people down to call the police," one caller said.