Facing a legislative committee short on patience and demanding answers, state prison officials offered few details Tuesday on why they have been unable to stop the flow of smuggled cell phones onto Texas' death row.

"Shut it down," state Sen. John Whitmire, D-Houston, a member of the Criminal Justice Legislative Oversight Committee, told prisons Director Brad Livingston. "If your job depended on keeping cell phones off death row, and I think that's an accurate statement, why can't you stop it?"

"This is a top priority," Livingston replied. "We are being vigilant."

At issue were new statistics showing that since a lockdown of Texas' 112 state prisons ended in early November, cell-phone smuggling has continued — 220 have been seized in the past two months.

The problem is centered at seven state prisons, where most of those phones have been confiscated. Whitmire and other members of the House-Senate committee questioned why a focused crackdown has not been ordered at those prisons — especially on death row, where eight cell phones have been found since November.

Smuggled cell phones in Texas prisons have been an issue since October, when death row inmate Richard Lee Tabler was busted for possessing a phone on which more than 2,800 calls had been made in one month — including several calls to Whitmire, who reported the contact to authorities.

Tabler told investigators that he bought the phone for $2,100 and that it was smuggled into the Polunsky Unit in East Texas by a guard. Tabler's mother and sister were arrested and charged with assisting contraband smuggling, and Gov. Rick Perry ordered the entire Texas prison system locked down for cell-by-cell searches.

About 140 cell phones, chargers and related gear were confiscated, including 18 phones from death row.

During Tuesday's hearing, John Moriarty, the prison system's inspector general, said four prison employees have been arrested in the continuing investigations into contraband smuggling — none in connection with the smuggled phones found on death row. Two are accused of smuggling in tobacco, one of smuggling a cell phone and one of bribery, he said.

Citing ongoing investigations, he provided no additional details.

Gina DeBottis, director of a special prosecutions unit, said no cell-phone cases have been prosecuted in at least two years. Moriarty and DeBottis told Whitmire that convicts facing death and life sentences may not be prosecuted because giving them longer sentences would do little good; cutting off privileges such as visitation may work better.

Whitmire said he wasn't satisfied with that explanation.

"If you're going to look the other way when they violate the law, where do you cut it off?" he asked. "It sends a horrible message" not to prosecute contraband cases, he said.

Prison officials also said that about 600 of their 6,000 surveillance cameras are broken; that Tabler may have obtained his cell phone from a trusty, instead of directly from a guard; and that Tabler may have borrowed the phone from another convict on death row, rather than owning it himself as originally thought.