The commander of the International Space Station has confirmed that a leak in its space capsule was caused deliberately and could have had “severe” consequences for him and his crew.

The leak was detected by NASA officials in late August, when flight controllers on Earth noticed a dip in the air pressure of the ISS.

It was identified by the crew as coming from a two millimetre hole on a section of the Russian-made Soyuz space capsule.

Nasa said at the time the crew were “never in any danger”, but photographs of the hole released later showed what appeared to be drill marks around it, sparking speculation about who carried out what appeared to be a deliberate attempt at sabotage.

Alexander Gerst, the German-born commander of the mission, has now scotched suggestions aired in sections of the Russian media that the hole was the work of US astronauts on a previous mission.

Instead Gerst appeared to suggest it was the fault of a botched repair job subsequently covered up by construction or maintenance crews on the ground.