A key official overseeing the ObamaCare launch last fall asked a subordinate to “delete” an email exchange on the matter, according to newly released records, fueling Republican concerns that the administration may be hiding internal discussions from Congress.

“Time and again, the self-proclaimed 'most transparent administration' has been anything but,” House Energy and Commerce Committee Chairman Fred Upton, R-Mich., said in a statement. “And now we know that when HealthCare.gov was crashing, those in charge were hitting the delete button behind the scenes.”

Upton and other GOP committee leaders on Friday released an email exchange from Oct. 5, 2013, shortly after HealthCare.gov launched to widespread problems. It showed Marilyn Tavenner, administrator for the Centers for Medicare and Medicaid Services, telling an employee in the public affairs office to “please delete this email.”

CMS spokesman Aaron Albright, though, told FoxNews.com that the email nevertheless was forwarded to staff to be preserved – it evidently was, since committee leaders later obtained it from the Department of Health and Human Services.

“The administrator forwarded this email to a press staffer solely for her awareness. She also copied immediate staff to retain the email, and it was preserved,” Albright said.

The development, though, comes after HHS earlier this month informed Congress that some of Tavenner’s emails may be lost – which followed the IRS admitting that emails from embattled ex-official Lois Lerner, embroiled in the scandal over the targeting of conservative groups, were also gone.

Republicans investigating the botched HealthCare.gov launch fired off a letter to Tavenner on Friday asking about that 2013 conversation, and whether the department has directed staff to delete or destroy other emails or documents pertaining to HealthCare.gov as well.

HHS has explained that since Tavenner receives as many as 12,000 emails a month, she would sometimes delete emails after either forwarding or copying the email to her staff to keep. However, some of these emails never made it to her staff.

An HHS spokesman said earlier this month that the department has confidence the “vast majority” of Tavenner’s emails can be retrieved, and they already have located more than 70,000. The department claimed any missing records do not speak to an attempt to conceal information.

Upton and Rep. Tim Murphy, R-Pa., pointed to the Oct. 5, 2013 email in questioning that claim.

“What was the Obama administration trying to hide?” Upton said. The lawmakers’ letter to Tavenner said the instruction to delete an email “contradicts” the agency’s claim that it tells personnel to retain records.

The 2013 email exchange started when Tavenner sent a note explaining how agency personnel were handling the flood of applications as the website itself failed. She explained they were taking PDF files that “look and act like a paper application,” but were shifting to take some information online. Another official wrote back questioning how that process would work.

Tavenner then looped in Julie Bataille, with the press office, and wrote: “Please delete this email-but please see if we can work on call script.”