SYDNEY (REUTERS) - The Australian authorities said a US Navy P-8 Poseidon, the most advanced search aircraft in the world, had been unable to find objects spotted earlier on Monday by a Chinese aircraft hunting for clues to the missing Malaysia Airlines flight MH370 in the Indian Ocean.

"A US Navy P-8 Poseidon aircraft was tasked to investigate reported object sightings by the Chinese aircraft made at 33,000 ft," a spokesman for the Australia Maritime Safety Authority (AMSA) said in an e-mailed response to Reuters.

"The objects were spotted by the Chinese aircraft as it was heading back to Perth. Drift modelling was undertaken on the sighting. The P-8 was unable to relocate the reported objects."

The Chinese Ilyushin IL-76 aircraft spotted two "relatively big" floating objects and several smaller white ones dispersed over several kilometres, Xinhua news agency reported earlier.