The crash site is an area of 15 square kilometres and experts could study only 45% of it, he said upon return of Malaysian experts from Ukraine.
Abu Bakar said the experts had had to leave Ukraine for security reasons but would go back since the work was not yet finished.
Experts could not take any debris from the crash site, he said, adding that this could be done only after their return to Ukraine.
He said one law enforcement officer would be sent from London to Kiev to get regular investigation updates, and two policemen would go to Amsterdam and Eindhoven.
Eighty-seven Malaysian police officers were working in Ukraine but could visit the crash site only two or three times during their ten-day stay, each time spending no more than three hours at the scene of the accident.
The plane en route from Amsterdam to Kuala Lumpur crashed in Ukraine’s eastern Donetsk region 60 km from the Russian border on July 17 and all of the 298 people aboard died.