Dutch investigators examining the Malaysia Airlines flight MH17 crash are to ask Russia to hand over radar data which Moscow claims proves the aircraft, with 298 passengers and crew on board, was shot down by a Ukrainian fighter jet.

Lead investigator Fred Westerbeke confirmed his team was preparing a “request for assistance” from Russia, which has always alleged a missile fired by a Ukrainian aircraft, and not a BUK surface-to-air missile fired by pro-Russian separatists, was responsible.

His investigation had ruled out the possibility of an accident or a terrorist attack, Mr Westerbeke said, and while the Boeing 777 could have been downed by a surface-to-air missile or by another jet, the evidence so far suggested the former was more likely.

A preliminary report last month found the aircraft, on a flight from Amsterdam to Kuala Lumpur, “broke up in the air, probably as a result of structural damage caused by a large number of high-velocity objects that penetrated the aircraft from outside”.

The Dutch investigators have been scrupulous not to apportion blame on the basis of incomplete evidence. However, just days ago the German foreign intelligence service, BND, said it had “unambiguous findings” which showed pro-Russian rebels in eastern Ukraine had been behind the attack.

BND director Gerhard Schindler dismissed the Russian claims of a Ukrainian jet in the vicinity as “false” and, referring to the deaths of four German citizens in the crash, said decisively, “It was pro-Russian separatists.”

As the Dutch investigation continues, Mr Westerbeke said he was also awaiting satellite images from the US – and said the final report could take “the entirety of next year, and possibly longer” to complete.

Political controversy over MH17 continues. Ukraine’s foreign minister, Pavlo Klimkin, said on Dutch television his government would not have objected if the Netherlands had spoken directly to the separatists immediately after the crash to get access to the dead.

This has created new difficulties for Prime Minister Mark Rutte, who refused to contact the separatists on the basis it would have amounted to recognising their breakaway region, and instead attempted to communicate through Organisation for Security and Co-operation in Europe officials.

Human cost

At the same time, the human cost of flight MH17 was recalled when the family of Newcastle United fan John Alder – killed with his friend Liam Sweeney on their way to see their team play in New Zealand – donated his match programme collection to the Sir Bobby Robson Foundation.

The body of 63-year-old Mr Alder was flown back to the UK from Hilversum last week. His sister, Joyce, said his family would say farewell at his funeral in the next few days.