Obama administration officials were trying on Friday to play down an embarrassing release of documents that suggest just six Americans managed to enrol for health insurance on the launch day of the troubled Obamacare website, insisting the figures do not represent “official totals”.

Internal notes released to the Republican-controlled House oversight committee and leaked to CBS on Thursday night revealed that software glitches and site-overload problems prevented all but a determined handful of customers from completing their applications.

Some 4.7m visitors overwhelmed the healthcare.gov website in the first 24 hours after its launch on 1 October. So-called “war room” notes distributed among contractors suggest only six enrollments had taken place by the morning of 2 October – spread among five insurers in different states. This had risen to 100 enrollments by the time of a subsequent internal meeting on the afternoon of 2 October, while 40,000 people were said to be in virtual “waiting room”.

The total, apparently based on online applications from the 36 states relying on the federal site, had only climbed to 248 by 3 October.

The extremely low figures, though a partial snapshot, fall far short of the seven million enrollments the administration is hoping for by 1 March, and may help explain why it has been reticent to release sign-up data until now.

However, the Department of Health and Human Services on Friday insisted it was still too early to draw a reliable picture of enrollment totals and suggested the war room notes were missing data from other important sources of applications.

"These appear to be notes, they do not include official enrollment statistics,” a department spokeswoman said. “We will release enrollment statistics on a monthly basis after coordinating information from different sources such as paper, online and call centers, verifying with insurers and collecting data from states.”

Officials from the White House down have repeatedly said they cannot yet publish accurate totals, which also raises questions about how contractors were able to share overnight “dashboard” information among themselves.

“As the [health] secretary [Kathleen Sebelius] said before Congress, we are focused on providing reliable and accurate information and we do not have that at this time due to the issues with 834 forms,” added the HHS spokeswoman. “We have always anticipated that the pace of enrollment will increase throughout the enrollment period."

The administration points to healthier figures for those applying – but not necessarily enrolled – which it says totalled 700,000 by 25 October. Half of those came from the federally-run online marketplace, which has now seen more than 20 million visitors in total.

This shows “the overwhelming interest in Americans learning more about their options for affordable healthcare”, claimed an official.

The administration also insists a slow start was to be expected, pointing to the example of Massachusetts in 2007, when only 0.3% or 123 people signed up for coverage during the first month of open enrollment, out of the 36,167 who ultimately signed up in the first year.

“As with other programs (for example, Medicare Advantage), we plan on issuing regular updates on implementation, including monthly enrollment statistics,” added the official. ”Our first release of enrollment data will likely be in the middle of November.

The White House spokesman Jay Carney said it the slow enrollment was no surprise. It was a "dog bites man story", based on "selected cherrypicked leaks from a Republican committee," he said. "We knew it was going to be a slow build and there is no question that it hasn't been helped by the poorly functioning website."