Everything we thought we knew about the universe could be wrong, according to new research analysing the faint echo of the Big Bang.

Based on data captured by the European Space Agency's Planck satellite, astronomers have argued the universe is not flat like previously thought.

Instead, researchers claim the universe is a curved and closed inflating sphere that loops back on itself – if you travelled in straight line, you would eventually return to where you started.

Planck collaboration maps the cosmic microwave background. Image: ESA and the Planck Collaboration (Supplied)

The study, published in the journal Nature Astronomy , suggests the finding present a "cosmological crisis" that calls for a "drastic rethinking of the current cosmological concordance model".

Astronomers' claims are based on the "gravitational lensing" effect predicted by Albert Einstein, which examines the way gravity bends the path of light.

Examining the cosmic microwave background - electromagnetic radiation left over from the Big Bang – they found it was more strongly gravitationally lensed than what would normally be expected.

"A closed Universe can provide a physical explanation for this effect, with the Planck cosmic microwave background spectra now preferring a positive curvature at more than the 99 per cent confidence level," the paper explained.

"Here, we further investigate the evidence for a closed Universe from Planck, showing that positive curvature naturally explains the anomalous lensing amplitude."

The claims have been refuted by astrophysicists George Efstathiou and Steven Gratton, who reported "strong evidence to support a spatially flat universe" after analysing the same Planck datasets and data from baryon acoustic oscillation surveys of dark energy.

While researchers are open to the suggestion it's systematic error in the Planck data that's making the universe look curved, they are calling for further research to be done before their findings are discredited completely.