It was an incredible tale of a German schoolboy spotting a miscalculation by the US space agency, proving the chances of an asteroid hitting the Earth were higher than initially believed.

But the amazing story of the whizzkid versus the space bureaucracy turned out to be wrong, the National Aeronautics and Space Administration said Wednesday.

The agency, sounding a bit like a weary math teacher, said its figures are correct when it comes to the asteroid Apophis, not the boy's.

"We stand by our numbers," NASA spokesman Dwayne Brown told AFP.

The agency that oversees space shuttle missions and unmanned space probes issued a statement after the German newspaper Potsdamer Neuerster Nachrichten reported on Tuesday that student Nico Marquardt had calculated there was a 1 in 450 chance that the Apophis asteroid will collide with Earth.

He argued in his project for a regional science competition that scientists at NASA had got it wrong when they estimated the chances of a collision at only 1 in 45,000.

But experts at the agency's Jet Propulsion Laboratory in Pasadena, California had no doubts about their calculations, Brown said.

The Near-Earth Object Program Office "has not changed its current estimates for the very low probability (1 in 45,000) of an Earth impact by the asteroid Apophis in 2036," Brown said in a statement.

And the newspaper's account was also inaccurate when it described NASA telling the European Space Agency that the German student's calculations were correct, Brown said.

"Contrary to recent press reports, NASA offices involved in near-Earth object research were not contacted and have had no correspondence with a young German student, who claims the Apophis impact probability is far higher than the current estimate," the statement said.

The student's estimates were reportedly based on the asteroid hitting a satellite in 2029.

"However, the asteroid will not pass near the main belt of geosynchronous satellites in 2029, and the chance of a collision with a satellite is exceedingly remote," it said.

While the German newspaper article had spread across the Internet, NASA said the probability of Apophis colliding with Earth remained at 1 in 45,000.