County spokeswoman Trisha Cofiell said the two inmates were returned to custody within 12 hours. She had no further comment. John A. Reilly Jr., superintendent of the prison, did not return calls seeking comment.
The jail has been run by the Community Education Center, a private company in West Caldwell, N.J., since 2009. Company spokesman Christopher Greeder had no comment.
One of the inmates released was Richard Dwayne Smith, 48, of North Philadelphia. He said in an interview he had been arrested in Philadelphia for driving under the influence and was returned on a probation violation to the jail in Delaware County, where he had a previous DUI conviction.
Smith said that when he was released June 7, he told prison officials he was not supposed to be set free but they didn't listen.
He said he returned to Philadelphia and spent the night with his girlfriend.
The next morning, Smith said, he had an attack of "consciousness" and called his probation officer to report he was out and find out how to return to prison.
Smith said deputy warden Mario Colucci helped negotiate the timing of his return.
Before surrendering, Smith said, he managed to squeeze in an "awesome breakfast."
He said it was business as usual when he returned to his cellblock. The guards all thought he was on a "writ" or temporary transfer to another facility for a court appointment.
Another inmate, Dominique Hilliard, was released on June 11 and returned within 12 hours, officials said.
Court papers show Hilliard, of Chester Township, is jailed on drug possession charges. No further information was available from county officials regarding his erroneous release.
In 2010, at least seven inmates were mistakenly released through paperwork errors or confusion over identities. As a result, two guards were suspended.
An investigation by the District Attorney's Office in 2010 found there was no criminal intent on the part of those involved with the releases, Erica Parham of the D.A.'s Office said.
District Attorney Jack Whelan and President Judge Chad F. Kenny did not return calls seeking comment about the latest releases.
Smith's grandmother Emma Ivey, 80, of North Philadelphia, said he called her when he was released. "What is wrong with those people in the office? Why would they do that?" Ivey asked. "They could have let a murderer out. You don't do that."
Contact Mari A. Schaefer at 610-892-9149, firstname.lastname@example.org, or follow @MariSchaefer on Twitter.