But Senate President Wayne Niederhauser, R-Sandy, said Swallow's exit raises serious questions about whether it's time to shut down the House probe.
"My understanding of the House investigation is they're investigating whether they should impeach or not, and if the need for impeachment goes away, I would question most of the Senate would question if any kind of House investigation needs to continue," Niederhauser said. "We've at least been supportive of what they're doing so far. We would have some big questions about whether that would need to continue, and we'd need some big justification if we're going to continue to support that financially."
House Minority Leader Jennifer Seelig, D-Salt Lake City, who is on the investigative committee, said the panel should finish its work even with Swallow bowing out.
"We have a job we were tasked to do and we need to finish that job," she said. "We at the very least need to come up with a report [of the findings]."
Jim Dabakis, chairman of the Utah Democratic Party and a state senator from Salt Lake City, was more direct, saying that shutting down the House probe would allow Republicans to sweep wrongdoing under the rug.
"Swallow is not the problem. He is the canary in the coal mine for the continuing culture of unethical and questionable behavior rotting the pillars of our state government," Dabakis said in a statement. "Our state leaders must stay the course, avoiding the urge and political pressures to close the investigation, whitewash the whole thing, and once again look the other way over a system that is eroding the very foundations of our Constitution."
Rep. Dan McCay, R-Riverton, said logically the investigation should end, adding that numerous representatives share that sentiment.
"We have a constitutional duty to deal with people in office," he said. "We no longer have a person in office, so the growing sentiment is we need to save the taxpayers money."
Dunnigan could exercise his authority to forgo calling any more meetings of the committee and block any more expenses paid to the attorneys and investigators the panel hired.
"There's no reason to call another meeting," McCay said.
Rep. Jim Nielson, R-Bountiful, said the House probe "is moot," but since "it was done with public funds, the findings should be shared with the public and the other investigations that are going on."
"Let's stop spending money," said Rep. David Lifferth, R-Eagle Mountain, "but let's make everything that has been discovered publicly available."
Rep. Janice Fisher, D-West Valley City, said she had mixed emotions about pressing on with the House probe. "Do we want to continue spending? Does it matter that we have answers to all the questions? There's obviously been some wrongdoing, because he resigned. But would money be better spent on something else?"
John Fellows, general counsel for the Legislature, said he believes that, even with Swallow out of office, the investigation could continue since the Legislature has both a constitutional power and a statutory charge to investigate.
Dunnigan teared up as he explained that his only goal is a fair investigation and whatever outcome it yields.
"My responsibility," he said, "is to the state House it's a body I greatly admire and to the people of Utah."
House investigators already have interviewed more than 140 witnesses, served 15 subpoenas and received more than 11,000 documents from Swallow and the attorney general's office.
Last month, the committee's special counsel expressed serious concerns about a significant amount of electronic data missing from Swallow's email account, office laptop and desktop computers, home computer and cellphone.
On Wednesday, Dunnigan reported that Swallow also had lost a campaign iPad earlier this year.
Throughout the process, Swallow has maintained his innocence, but alleged last month that investigators would sift through everything he had done until they found some minor misdeed to justify the probe's projected $3 million price tag.