Democratic nominee Hillary Clinton speaks to and meets voters during a rally at Frontline Outreach and Youth Center in Orlando on Wednesday, Sept. 21, 2016. (Melina Mara/The Washington Post)

A computer specialist who maintained Hillary Clinton’s private email server while she was secretary of state told the FBI that fellow State Department officials had expressed concerns to him about whether the system was properly retaining public records, according to newly released documents from the now-completed inquiry.

Bryan Pagliano, a former Clinton campaign aide who set up and maintained the server during her time as secretary, said that some agency officials had asked him in late 2009 or early 2010 to convey to Clinton’s “inner circle” that her use of a private server could pose a “federal records retention issue,” the documents show.

In response, Pagliano said, chief of staff Cheryl Mills told him that other secretaries of state, notably Clinton’s predecessor Colin Powell, had also used private email, according to the documents.

The new details come from 189 pages of investigative notes from the FBI’s examination of Clinton’s use of a private server released by the agency late Friday.

The new details, including the revelation that Pagliano had received warnings about the system, are likely to continue to fuel Republican presidential nominee Donald Trump’s attacks on Clinton, the Democratic nominee, for her use of the email system.

The FBI Sept. 2 published a detailed report on its investigation into Democratic presidential candidate Hillary Clinton’s use of a private email server while she was secretary of state. (Sarah Parnass/The Washington Post)

In a statement, Clinton campaign spokesman Brian Fallon said, “These materials further demonstrate why the Justice Department believed there was no basis to move forward with this case.”

Republicans have been pressuring the FBI to make public more material from the investigation, which ended in July with a finding by FBI Director James B. Comey that Clinton should not be charged with a crime though she had been “extremely careless” with classified information.

The documents include summaries of nearly four dozen interviews with top Clinton aides, tech workers, other state department officials, and even a Romanian hacker. Agents interviewed some multiple times, and some of the summaries are heavily redacted. The FBI had already released a summary of Clinton’s June interview.

Pagliano agreed to speak to the FBI under an immunity agreement. Officials confirmed Friday that Mills, too, had received a limited immunity in the case. Her immunity deal did not apply to her interviews with FBI, but rather was limited to a search of computers she turned over.

Trump spokesman Jason Miller said the immunity agreements showed that Clinton’s email use was “without a doubt a criminal scheme.” Beth Wilkinson, Mills’s attorney, however, said Mills had fully cooperated with the FBI probe, including voluntarily sitting for interviews. Wilkinson said Mills accepted an immunity agreement regarding the contents of her laptop “because of the confusion surrounding the various agencies’ positions on the after-the-fact classification decisions.”

The documents show that some officials, when asked by FBI agents to review specific email exchanges that had been sent using unclassified email, expressed alarm.

1 of 9 Full Screen Autoplay Close Skip Ad × Takeaways from Hillary Clinton’s e-mails View Photos Clinton has come under fire for using a private e-mail address during her time as secretary of state. The emails are being screened and released in batches. Here are some things we’ve learned from them. Caption Clinton has come under fire for using a private email address during her time as secretary of state. The emails are being screened and released in batches. Here are some things we’ve learned from them. Top-secret information in e-mails Democratic presidential candidate Hillary Clinton has previously stated that classified information never traveled across her private server. However, the State Department has acknowledged that "top secret" information was in seven email chains sent or received by her. Richard Drew/AP Buy Photo Wait 1 second to continue.

“Wow,” responded one official, whose name was withheld from release by the FBI, before declining to answer further questions about it. The FBI indicated that as the official was being escorted to the elevator following his interview, he told an agent that “after seeing the above referenced documents, he now understood why people were concerned about this matter.”

According to FBI agents, Michael Morell, who served as deputy director of the CIA from 2010 to 2013, conceded in one case that information in an email shown to him by agents “could be potentially damaging to the operation” described in the email. In other instances, however, he told agents that information in emails, while classified, would pose little risk to national security if it had become public.

Morell, who has since left government service and endorsed Clinton, could not be reached for comment.

The documents show that most of those interviewed, when shown emails containing information now deemed classified, objected to the designation or otherwise said they did not believe their exchange on unclassified systems was concerning.

The documents contain a number of modest, some even comical revelations. For instance, Clinton aide Monica Hanley had to acknowledge that the iPad the FBI had seized from her had once belonged to Clinton. The former secretary had gifted the used device to her employee.

But some of the information is likely to raise more questions and criticisms. Hanley, for example, received verbal counseling after Diplomatic Security found she had left a classified page from a Clinton briefing book in a Russian hotel suite she shared with Clinton. She was told the book and document never should have been brought into the suite.

And there is reference in some of the interviews to Clinton’s use of a Gmail account while secretary, at least during one foreign trip to Croatia when storms were disrupting her receipt of emails.

Clinton’s campaign has not previously indicated she used a Gmail account, instead indicating that she used one AT&T account during her first few months in office and then exclusively used the account routed through her private server for the remainder of her tenure.