The Intercept reported that a campaign vendor subcontracted ProCom, a New Jersey-based call center company, to make calls on the campaign’s behalf. Inmates at the Dr. Eddie Warrior Correctional Center, a minimum security women’s prison with a capacity over 900, called potential voters in California. As required, each inmate stated that their calls were paid for by the Bloomberg campaign, at the end of each exchange.

The Bloomberg campaign told The Intercept that they were not aware that prison labor was used until the outlet brought it to their attention. “We didn’t know about this and we never would have allowed it if we had,” Bloomberg spokesperson Julie Wood told the outlet. “We don’t believe in this practice and we’ve now ended our relationship with the subcontractor in question.”

In a press release shared with Newsweek, Bloomberg expressed disapproval for ProCom’s practice. “Earlier today, a news outlet reported that prison workers were being used by a subcontractor to make telephone calls on behalf of my campaign. I’m not attacking the news: the story was fundamentally accurate,” the statement read.

“We only learned about this when the reporter called us, but as soon as we discovered which vendor’s subcontractor had done this, we immediately ended our relationship with the company and the people who hired them,” Bloomberg reiterated.

In the future, the billionaire former mayor’s campaign is asking vendors to look further into their subcontractors. “We do not support this practice and we are making sure our vendors more properly vet their subcontractors moving forward.”

John Scallan, a ProCom co-founder, told The Intercept that the company pays the Oklahoma Department of Corrections $7.25 an hour, which is Oklahoma’s minimum wage. The Oklahoma DOC website notes that inmates can earn up to $20 per month performing “institutional job assignments,” as The Intercept reported, though the explanation also goes on to say that “some inmates … may receive more pay working for Oklahoma Correctional Industries (OCI).”

Scallan disputed the idea that ProCom was responsible for the low wages “I can tell you unequivocally, that is not us,” he told The Intercept. “Some of them are making that much every day.”

In a statement, a ProCom spokesperson reiterated to Newsweek that the company pays the state’s minimum wage to the DOC, and that the DOC, in turn, pays their incarcerated workforce. The company also stated that it helps inmates by giving them skills that can be used to reintegrate into society. “Inmates employed by ProCom receive marketable job training and skills that allow them to both earn money while they’re incarcerated and position themselves for gainful employment when their prison terms end, including with ProCom,”

“A lot of politicians and advocacy organizations say they want to tackle the recidivism problem that plagues our country’s criminal justice system. But ProCom does more than pay lip service to this serious problem. As our employees will tell you, we help them get their lives back and be productive members of society—and positive influences on their families,” the statement read.

Oklahoma Department of Corrections Public Information Manager Matt Elliot confirmed to Newsweek that the wage inmates receive is well below what ProCom has paid. Though it also seemed to be higher than the $20 and $27.09 pay caps referenced by The Intercept.

“The pay that’s been reported is incorrect. Inmates can receive $1.45 an hour working for call centers, working eight hours a day, five days a week. Inmates may work additional hours but only with permission from the Director of Oklahoma Correctional Industries,” Elliot told Newsweek. The hourly rate provided by Elliot amounted to approximately $230 per month.

According to Forbes, Bloomberg’s net-worth is over $55 billion. As previously reported, if the candidate employs similar campaigns to those he ran while running for mayor, his campaign may spend over $6 billion.