The tiny hole aboard the International Space Station (ISS) that caused so much drama in August of last year is still producing controversy, over a year later. According to new reports, Russia now knows the source of the hole, but it doesn't look like NASA has been informed.

While talking to the participants of a youth science conference themed around cosmonautics, Dmitry Rogozin, the head of Russian space agency Roscosmos, revealed that the investigation into the incident had been fruitful.

"[The hole] was in the living quarters [of the capsule], it has long since burned up upon reentry. We took all the samples. We know exactly what happened, but we won't tell you anything," he said, as reported by Russian state news agency RIA Novosti.

"We do need to retain some sort of secrecy," he added, likely as a tongue-in-cheek remark, considering his young audience.

The hole was discovered in August 2019 when astronauts aboard the ISS noticed that they were slowly but steadily losing air pressure.

A search of the station revealed the source - a tiny, 2 millimetre hole in the Soyuz MS-09 spacecraft, the Roscosmos shuttle used to ferry astronauts to and from the ISS. When it arrives, it docks onto the Rassvet module and is used as living quarters and a potential life raft until part of it returns to Earth, carrying astronauts whose mission has concluded.

The astronauts plugged the hole with epoxy and tape, and embarked on an investigation, even conducting a spacewalk to inspect the outside of the spacecraft to determine if the hole had been punched by a micrometeoroid - because if tiny rocks could punch holes in the ISS, that would be valuable information.

Later, it was determined that the hole had been created by a drill, although whether accidentally or on purpose, or on the ground or in space (the latter of which would be highly unlikely due to Newtonian physics), was yet to be revealed. The landing module of the spacecraft returned safely to Earth in December 2018, while the detaching living quarters - complete with the hole - burned up on reentry.

Roscosmos continued to conduct its investigation, and RIA Novosti reported that it was a mistake made during manufacturing - which Rogozin swiftly denied. What caused the hole is yet to be officially revealed.

Whether or not Rogozin's remarks were tongue-in-cheek, the results of the investigation have yet to be communicated with NASA, according to the US agency's administrator Jim Bridenstine.

"They have not told me anything," Bridenstine told the Houston Chronicle during an energy conference. "I don't want to let one item set (the relationship) back, but it is clearly not acceptable that there are holes in the International Space Station."

He also said he would be speaking with Rogozin.

The relationship between the two space agencies is deeply important for NASA, which shut down its own shuttle program in 2011. Since then, it has relied upon Russia's Soyuz program to transport its astronauts to the ISS, at a cost ranging from $21.3 million to $81.9 million per astronaut per round trip.

NASA's uncrewed supply missions are handled by SpaceX's Dragon and Northrop Grumman's Cygnus.

SpaceX is currently in the testing phase of its Dragon 2 crew spacecraft, and it intends to launch its first astronaut flight by 15 November of this year. Boeing's CST-100 Starliner astronaut transport is also in development, hoping to launch a crew by 30 November.

However, both projects have been bedeviled by delays, and whether they will meet those deadlines remains an open question.