As a system wide prison lockdown in Texas stretches into its second week, investigators are probing whether women in Europe gave money to death row inmates to buy prohibited cell phones that were allegedly used to direct crimes from behind bars.
"These cell phones are a direct threat to public safety," John Moriarty, the Texas prison system's inspector general, told ABCNews.com.
State authorities have thwarted attempts at narcotics trafficking and solicitation of capital murder from prisoners who had the illicit phones, he said.
A shakedown of the state's 112 facilities began last week after State Sen. John Whitmire received what he said was a threatening call from Richard Tabler, a convicted double-murderer who is currently awaiting execution on death row at the Polunsky Unit in Livingston, Tex.
After the call, Gov. Rick Perry put the entire prison system on mandatory lockdown, restricting movement for all of the system's 156,000 prisoners.
Authorities are investigating a large narcotics ring involving cell phones within the prison and people on the outside, Whitmire told ABCNews.com.
According to a prison representative, a lockdown means many inmates are confined to their cells for most of the day -- they are no longer permitted to leave for educational programs, time in the recreation yard or to go to the showers.
Whitmire told ABCNews.com that he became alarmed when Tabler not only mentioned the names and ages of his two daughters but also spoke flippantly about how easy it was for him to get a cell phone behind bars.
"I kept asking [Tabler] how he was calling me, and he just responded, 'I'm on a cell phone,'" said Whitmire, who is chairman of the state Senate Criminal Justice Committee.
"I asked him how he got it and he quickly said, '$2,100,'" he added. "He also told me had a charger."
Authorities said they determined that Tabler, 29, had shared his phone with at least nine other inmates; together, they are estimated to have placed as many as 2,800 calls in the last 30 days.
Moriarty said the "substantial" number of international calls made from the cell phones led investigators to look into whether women involved in anti-death penalty movements across Europe may be responsible for financing some of the smuggled devices.
"We're very familiar with the anti-death penalty movement folks who are foreign nationals," said Moriarty. "It's not unusual for them to visit death row inmates and have contact with individuals on Texas' death row, and overall we don't have any issues with that unless they engage in criminal activity."
"If [money they are providing is going toward purchasing cell phones for inmates,] that's obviously an issue."
Officials at the Texas prison system, the second largest in the country, are trying to find out how the phones moved from the outside world to behind bars.
Moriarty concedes that it would be "very, very difficult" for inmates to get phones "without inside help."
No prison employees or corrections officers have been arrested or charged yet in the investigation, said Moriarty.
Since the lockdown began at 6 p.m. Oct. 20, 71 cell phones, 65 chargers and six SIM cards -- devices used to transfer information from one phone to another -- have been found by prison authorities, according to Michelle Lyons, the spokeswoman for the Texas Department of Criminal Justice.