PETALING JAYA - Where the MH370 ended in the southern Indian Ocean was based on new analysis by UK investigators and the British satellite firm Inmarsat.
As stated by Prime Minister Datuk Seri Najib Tun Razak, Inmarsat used new techniques to detect the plane's course.
The UK's Air Accidents Investigation Branch, which probes serious civil aircraft incidents, was also involved.
According to BBC, Inmarsat gave the Air Accidents Investigation Branch (AAIB) the new data on Sunday - adding it needed to be checked before it was made public.
The firm said its latest calculation involved a large amount of data analysis, focusing on a number of factors including the movements of other aircraft.
It involved an entirely new way of modelling which is why the analysis took some time, the firm added.
A spokeswoman for the AAIB said as set out by Najib, "we have been working with the UK company Inmarsat, using satellite data to determine the area on which to focus the search.
"We are not able to comment further on this investigation, which is being led by the Malaysian authorities."
Oceanographer Dr Simon Boxall, from the University of Southampton, also told the BBC it was significant that Inmarsat had been tracking data, rather than locations.
"The algorithms and the techniques they've applied to try and locate to within a certain area where the last transmission was made is really quite phenomenal - but also quite tragic because it does show this plane was heading to an open area of ocean."
"They [Inmarsat] started from scratch. They've probably crammed almost a year's worth of research into maybe a couple of weeks so it's not a routine calculation they would ever, ever make.
"So they've been looking at all the signals they have, all the recordings they have, and processing that many times over to try and pinpoint where the plane's signal came from. Technologically it's really quite astounding," said Dr Boxall.
He said that Inmarsat must have run through its calculation a number of times and "wouldn't have released this sort of information without being 100 per cent certain".
Philip Baum, editor of Aviation Security International Magazine, stressed that the mystery of flight MH370's disappearance had not been solved yet.
"We still believe there was a deliberate act that took place on board the flight deck inside the cockpit that resulted in the aircraft turning and heading south," he said.
"Indeed, south of the next landmass would have been Antarctica. So until we find the black box we're really not going to know anything more."
Airline pilot Peter Benn said finding some of the wreckage could help explain what happened to the plane.
"I don't think anyone should underestimate the magnitude of that task. It is a vast undertaking, suffice to say if some debris can be recovered it would provide an awful lot of clues," he said.