"During the descent, the mechanism for docking with the ISS (International Space Station) turned out to be switched on," the ITAR-TASS news agency quoted him as saying.

Budarin and two US astronauts, Kenneth Bowersox and Donald Pettit, made a much steeper than anticipated entry for their landing on the plains of Kazakhstan Sunday, enduring a crushing gravitational effect that made it difficult for them to breathe.

Their capsule landed nearly 500 kilometres (310 miles) from its intended destination, and it took more than two hours for rescue services to locate them.

The three astronauts denied on Tuesday that they precipitated the off-target landing by pressing the wrong button.

SPACE.WIRE