When Philadelphia prison officials witnessed a few years ago a spike in street drugs and cellphones seized from inmates in city jails, they started to investigate their own. And, when that was not enough, they asked the FBI for help.

A sting operation in which agents used prison informants to bait the suspects resulted in federal charges announced Wednesday against six current or former correctional officers accused of delivering OxyContin and cellphones, both which are forbidden to inmates, in exchange for cash.

The guards, authorities said, got $500 to $1,500 for their deliveries, money that could lead to decades in prison.

"It is regrettable that sworn staff, who have an obligation to provide a lawful and secure environment in our jails, chose to offer their badges for sale and pervert their authority for personal gain," said Louis Giorla, Philadelphia prisons commissioner, at a news conference.

Current prison system officers charged are: John Wesley Herder, 49, who works at the Curran-Fromhold Correctional Facility; Bryant Fields, 43, employed at the Detention Center; George Kindle, 29, employed at the House of Corrections; and Joseph Romano, 31, who used to work at the Philadelphia Industrial Correctional Center and now works at the Riverside Correctional Facility.

Also indicted were former House of Corrections guard Marc Thompson, 23, and former Curran-Fromhold guard Dupree Myers, 27.

All six officers were charged with attempted extortion and distribution of controlled substances. If convicted, they face a maximum sentence of 40 years in prison; Kindle, twice caught allegedly receiving payments, faces 80 years.

Herder, a nine-year veteran, faces additional charges of giving false statements to federal law enforcement agents.

The correctional officers earned an average of $60,000 this year in salary and overtime pay, according to city payroll records.

There were no indications, authorities said, that the six men coordinated their alleged schemes.

Giorla said his staff conducted an internal investigation to address the growing number of seizures. Once the FBI was involved, authorities used prison informants to engage officers suspected of smuggling.

Prosecutors said arrangements were made between the prisoners and guards to meet with an outside associate, who also worked for the government. The purported associate provided the contraband and cash, later brought into the prisons by the officers. The exchanges happened between October 2013 and December 2014, prosecutors said.

"Prison safety depends on prison guards acting with honesty and integrity," U.S. Attorney Zane David Memeger said at the news conference. "When the people we trust to maintain the proper prison environment supply prisoners with drugs and contraband, they completely undermine the goals of incarceration."

Giorla wants to expand the prison system's future investigative capabilities.

"Our facilities aren't saturated with video cameras at this time," Giorla said. "We're hoping to rectify that, particularly in our older facilities."

Three of the six correctional officers were arraigned Wednesday in federal court, and the other three will be arraigned next week, officials said. All pleaded not guilty, and were released on bond.

mgelb@philly.com 215-854-2928 @MattGelb