Inmates Jonathan Tieu, 20, Hossein Nayeri, 37, and Bac Duong, 43 (l.-r.), are seen in an undated combination photo released by the Orange County, California, Sheriff's Department. Reuters

UPDATE: 11:53 p.m. EST -- A security consultant said Monday that three inmates who escaped from a jail in California may have had inside help, the Associated Press reported. The men had sawed through a metal grate, crawled through plumbing tunnels and used bed linens to make a rope to escape, authorities said.

Kevin Tamez, a managing partner for MPM Group, a Philadelphia firm that consults on prison security, management and infrastructure, told AP that someone might have sent blueprints or told them details about the bowels of the jail. “If I were whoever's investigating, there are some people who would be on a polygraph, I guarantee you,” Tamez said, according to AP, adding: “They had to have had some inside help.”

However, Lt. Jeff Hallock, a spokesman for the Orange County Sheriff's Department, said there was no evidence that the trio received help.

The three men were awaiting trials for unrelated violent crimes at the Men's Central Jail and were being held in a dormitory with 65 other men.

UPDATE: 5:50 p.m. EST -- The sheriff's department in Orange County, California, has offered a $50,000 reward for information leading to the apprehension of three escaped inmates. In a tweet, the department listed a hot line phone number, 714-628-7085.

Original story:

Local and federal officials continued to hunt Monday for three inmates who escaped from a jail in Orange County, California, on Friday, the Orange County Register reported. The inmates were considered to be armed and dangerous, with two of the men believed to have ties to Vietnamese gangs.

Officials reportedly suspect that Hossein Nayeri, 37, Jonathan Tieu, 20, and Bac Duong, 43, have not left Southern California and are being harbored nearby. Nayeri has been accused of kidnapping and torturing a marijuana dispensary owner, Tieu is facing a murder charge for a gang-related killing and Duong has been accused of attempted murder. Tieu and Duong were reported by the Orange County Register as being Vietnamese gang members.

It took officials roughly 16 hours Friday to learn that the men were missing, and an additional three to confirm that they had indeed escaped. The inmates reportedly managed to escape the maximum-security jail in Santa Ana, California, by cutting through steel bars, wiggling their way through plumbing tunnels and rappelling off a roof. Investigators believe they managed to slip out sometime shortly after a 5 a.m. head count Friday morning. Authorities are also investigating whether a fight Friday night was staged deliberately to delay a head count to help hide the escapees, the Los Angeles Times reported.

“It appears to be a very sophisticated operation, where they were allowed to go through security access points and had some tools that allowed them to do that,” said Sheriff Sandra Hutchens, the Orange County Register reported. “Where they got those tools and how that occurred — we are still looking into that.”

U.S. marshals offered a $30,000 reward for information leading to the capture of the convicts, which is in addition to a $20,000 reward already offered by the FBI. The trio’s jailbreak prompted sheriff’s officials to re-evaluate jailhouse security, which has been criticized in recent years by county watchdogs.