A criminal investigation into IT contractors employed by dozens of House Democrats is sparking broader concerns about continuing access to sensitive government emails, amid new allegations of illicit activity beyond Capitol Hill.

The investigation was announced last month by the U.S. Capitol Police and purportedly focuses on the contractors' access to House computers and whether they took hardware and made questionable IT-related purchases.

A police spokesman, while declining to go into detail, told Fox News this week that the case remains opens and focuses on “the actions of House IT support staff.”

But a high-level House staffer acknowledged Monday to Fox News that the probe has raised concerns about emails being hacked.

Official documents and multiple sources say at least five contractors -- including brothers Imran, Jamal and Abid Awan -- are the focus of the probe but that as many as six people could be involved.

The others purportedly involved are Imran’s wife, Hina Alvi, and Rao Abbas, who is not part of the family.

They allegedly removed hundreds of thousands of dollars of equipment from offices, including computers and servers, and ran a procurement scheme in which they bought equipment, then overcharged the House administrative office that assigns such contractors to members.

Sources also say the contractors, including one who worked for Florida Democratic Rep. Debbie Wasserman Schultz, had “unauthorized access” to the House computer system.

The connection to the former Democratic National Committee boss has sparked questions about whether the contractors could have ties to the DNC hack last summer, which was seen to hurt Hillary Clinton’s ultimately failed White House bid -- or whether Russia or other outside operatives accessed emails that the contractors allegedly put on a cloud server.

There have been no reports or evidence so far showing the contractors were involved in a hacking incident.

House Democrats have stood by the contractors, privately and publicly suggesting their Muslim and Pakistani heritage prompted the probe and is contributing to fear-mongering.

Wasserman Schultz as of Friday was still employing Imran Awan, 36, as an adviser, despite his access to the chamber’s computer system having been revoked.

Rep. Gregory Meeks, D-N.Y., kept Alvi, 33, employed until about two weeks ago.

“I have seen no evidence that they were doing anything that was nefarious,” he told Politico. “I wanted to be sure individuals are not being singled out because of their nationalities or their religion.”

But other troubling allegations have surfaced.

Police in January were called to the northern Virginia home of a woman identified in the incident report as the stepmother of the Awan brothers, as first reported by The Daily Caller News Foundation.

The woman alleged the brothers were keeping her away from her dying husband.

Abid Awan told police her bedside visits were causing their father additional stress and that he had full power of attorney over him, then produced “an unsigned, undated document as proof.”

A family member told a foundation reporter that the stepsons had kept the women in a “sort of illegal captivity” from October 2016 apparently until their father’s death in early February in a plot to get his life-insurance money. And they threatened her in an effort to get money that their father had stashed in Pakistan, the family member said.

The Daily Caller story said the stepmother has filed a separate police complaint alleging insurance fraud.

According to LegiStorm.com, which tracks congressional pay, the contractors’ Capitol Hill work started in 2004 with at least two making six-figure salaries, including Abid Awan last year earning $166,944.

But Awan also had money troubles, contributing to concerns about the contractors' access to sensitive emails and how that could be used. Awan declared bankruptcy in 2012 with more than $1.1 million in debt.

Court documents show the debt included roughly $51,150 to the Congressional Credit Union, for two cars and a credit line. And Virginia court records show he has had 19 violations since 2009, mostly traffic-related offenses.

Database searches found no major criminal charges for any of the contractors allegedly under investigation.

The contractors could not be reached for comment.

Fox News' Chad Pergram contributed to this report.

