The head of the Dutch-led international team investigating the Malaysian Airline Flight 17 disaster says his group has retrieved additional DNA samples from 25 victims at a mortuary in Donetsk in eastern Ukraine.

Pieter-Jaap Aalbersberg said from Kiev Wednesday the team had also recovered personal belongings of 27 victims at the mortuary.

Flight 17 was shot down in an area held by pro-Russia separatists in eastern Ukraine on July 17, killing all 298 people on board.

Remains of around 200 victims were transferred to the Netherlands earlier and are being painstakingly identified. Remains of another 80 people are believed to still lay unrecovered at the crash site.

Investigators from Aalbersberg's team reached the crash site for the first time in days Thursday, braving clashes between separatists and Ukrainian forces.