Chinese satellite pictures of debris in the South China Sea are not connected to the missing Malaysian airliner, Malaysia's transport minister says.
Hishammuddin Hussein also denied a US report that Flight MH370 might have flown for hours after contact was lost.
Chinese state TV is still treating the pictures as relevant and says a warship is continuing to hunt for the debris.
The plane went missing early on Saturday with 239 people on board. The search now includes the Indian Ocean.
The minister said the disappearance of the Boeing 777-200ER aircraft was unprecedented.
Mr Hussein told reporters at Kuala Lumpur International Airport that the Chinese embassy in the Malaysian capital had said the satellite images were released by mistake and "did not show any debris from MH370".
The grainy satellite images were released by China's State Administration of Science on Wednesday.
Despite the denial, state TV in China says a warship is continuing to search for the debris spotted in the South China Sea.
One commentator dismissed Mr Hussein's comments, and the report said China would continue to analyse new satellite images.
'Everything was normal'
Meanwhile, the Indian army has confirmed it is joining the search for flight MH370 after focus was extended to Andaman Sea, in the Indian Ocean.
India will be sending military ships and aircraft to try to locate a possible crash site, it said.
Speaking to reporters on Thursday, Mr Hussein denied a report in the Wall Street Journal that the plane had sent engine data to the ground for more than four hours after it lost contact with air traffic control.
He said that his team had spoken to Malaysia Airlines and Rolls-Royce, the engine's manufacturers, who both said the report was "inaccurate".
"The last transmission from the aircraft was at 01:07 which indicated that everything was normal," Mr Hussein said.
He added that the aircraft had been fully serviced, with the last maintenance conducted on 23 February 2014.
Mr Hussein said that efforts to locate the aircraft were ongoing, promising to "spare nothing in our efforts to find MH370".
"There are currently 43 ships and 40 aircraft searching the South China Sea and Straits of Malacca," he said.
In a separate press conference in Vietnam, an air traffic official said five ships and three aircraft had been sent on Thursday to the area indicated by the Chinese satellite images but had found nothing.
The BBC's Nga Pham in Vietnam says the official declined to answer a question on whether he was frustrated with Malaysia's communication and co-ordination, referring the matter to the foreign ministry.
He said Vietnam would continue to search for the plane on Friday.