Bernie Sanders Said to Be ‘Very Unhappy’ With Staffers Who Accessed Hillary Clinton Campaign Data

— -- Bernie Sanders' campaign manager said today the candidate is "very unhappy" that people on his staff would access propriety data of Hillary Clinton's campaign.

One of the four staffers involved who accessed the Clinton campaign's propriety data has been fired, but Sanders campaign manager Jeff Weaver refused to say whether the other three would also be fired in the wake of a Democratic National Committee data breach.

"That's what we're investigating, and we'll take it wherever it goes," Weaver told ABC News ahead of tonight's Democratic presidential debate. "We’re going to discipline more if we find out, once we find out all the details."

Tune in Saturday at 8/7 PM CT to watch the ABC News Democratic Debate in New Hampshire

Weaver said the Democratic National Committee issued a "death penalty for our campaign" by cutting the campaign off from the database.

Weaver said Sanders is "very unhappy that these young people would do this. He holds himself and everybody else to ethical standards."

Weaver contended the DNC impeded the investigation by temporarily restricting the Sanders campaign’s access to data. As of Saturday morning, Sanders campaign access to the data has been restored.

“By putting us out of our data, we weren’t able to look around into and see what our people were doing from our end,” Weaver said. “Problem number two is, they apparently have generated a number of logs and a number of documents which they have distributed to the media and the Clinton campaign of which they have refused to share with us. If they really want to help us get to the bottom of this, we would really appreciate seeing the logs so that we could better hone in on what they think other people did.”

And for why the others haven’t been fired yet, he said they want to “know exactly what people knew and what they saw and what their intent was.” He emphasized that it could have all been accidental.

“It may be that there were some people, accidentally, while looking at Sanders data, saw some Clinton data purely inadvertently and nothing,” Weaver told ABC News. “I want to treat people fairly.”

Democratic National Committee Chairwoman Debbie Wasserman Schultz told ABC News she personally called Sanders to let him know about the breach.

"Unfortunately at that point we had to suspend his campaign's access to the voter file because we were not getting the answers to the questions they had --and we didn't know what they had -- and couldn't allow them to manipulate other campaigns' information that they weren't entitled to have," she said.

With just hours to go before tonight’s showdown between his candidate, Clinton and former Maryland Gov. Martin O’Malley, Weaver said that the “biggest” impediment to Sanders’ debate prep has been a busy Senate schedule.

Get real-time updates as this story unfolds. To start, just "star" this story in ABC News' phone app. Download ABC News for iPhone here or ABC News for Android here.