AVENAL, Calif. (AP) — California prison officials will start using new cellphone blocking technology at a Central Valley prison next week, the first step to rolling it out system-wide.

Avenal State Prison, 60 miles south of Fresno, will start on Monday to block inmates from making calls on smuggled cell phones.

The company Global Tel Link installed the technology for free. The company owns the pay phones in California's prisons and it now expects to see profits from collect calls soar.

California prison guards confiscated nearly 11,000 contraband phones last year, a sharp increase from 2007 when only 1,400 were found. Prison officials say the phones have been used by inmates to organize and run criminal enterprises.

Officials say the technology will be installed at the state's 33 prisons within three years.