Torez, Ukraine: The value of a hostage is in being alive. But in the steamy heat of this Ukrainian summer, the decaying bodies of 38 Australians among the near-300 killed in the crash of flight MH17 were held hostage till late Monday, when separatist rebels relented, allowing the so-called ‘train of death’ to pull away from the local railway station and, in a nearby town, they were to surrender the aircraft’s black-box voice and data recorders.

Rebel fighters who control the crash scene, near the village of Hrabove, had loaded them on to a Soviet-era refrigerated train over which they kept a tight armed guard; and for a while, they had claimed not to have the black boxes.

But by late Monday, their actions might have gone some way to easing rising international tension in the wake of the crash. It took a while to get there.

When a team from the Organisation for Cooperation and Security in Europe inspected the wagons at the Torez railway station on Monday morning, their pleas for the train to move were rebuffed.

As the overpowering stench of death wafted from the open doors of one of the wagons, the black body bags could be seen piled up, like so many sacks of potatoes. With all present wearing face-masks or making do with any fabric they could fine to cover their faces in the 29 degree Celsius heat, the leader of the OSCE team, Alexander Hug, could be heard insisting several times to an unidentified rebel negotiator – “This train must move today – will it?”

Accompanied by one of the first foreign experts to come to the separatist-controlled east of the country, Dutch forensic expert Peter Van Vliet, Mr Hug then appealed to a sense of decency, telling the 40-something rebel who, when I asked, refused to identify himself: “this is not good for the experts and their families.”

That failed negotiation took place on the platform, in the blazing sun as armed rebels, some masked, stood guard over the fetid but precious cargo. But when it was over, Mr Hug alluded to plans for a subsequent private session after which, he said more in hope than in certainty, there might be a timetable and a destination for the five-wagon train.

And indeed there was – at 7pm the train moved out, heading slightly west of north on creaking rail had infrastructure, for the city of Kharvik, where Dutch military transports were ready to fly them to the Netherlands. And just two hours later, at Donetsk, about 70km west of Torez, the black boxes were due to be handed over to Malaysian officials.

The Ukrainian government had already established a crash crisis centre at Kharkiv to receive the bodies. But as recently as Monday morning there was a suggestion from within the rebel camp that the train might be shunted south, to the Black Sea port city of Mariupol.

Australian specialists had already joined others from the Netherlands at on Monday, along with German, American and British experts.

The inspection of the bodies on Monday also might have provided some comfort for grieving families and friends of the dead. Despite a loss of power to the wagons’ refrigeration overnight Sunday, the Dutch expert Mr Van Vliet told reporters at the station: “I have inspected the train and the wagons and the quality of the storage is good … acceptable.”

That meeting at Torez took place as Moscow came under increasing pressure to use its considerable influence to make the separatist rebels less bloody minded to have them cooperate with international demands for a speedy repatriation of the bodies and for a thorough investigation of the crash to commence in the rebel held east of the country.

In Washington, President Barack Obama obliquely skewered his Russian counterpart, Vladimir Putin, demanded full investigative access to the crash site. Accusing the separatists of taking evidence from the site, Obama asked: "What exactly are they trying to hide?"

After trucking the bodies overnight Saturday to Torez, 15km from the crash site, the rebels said that there were 196 bodies on the train. About 40 more are believed to be stored in the morgue at nearby Donetsk – there are the crash victims whose bodies fell into village and farm homes and yards as Malaysian Airlines flight MH17 plummeted to earth after being struck by a missile last Thursday.

More bodies were at the crash site late Sunday – I saw six body bags and an American colleague reported seeing 18 elsewhere on the 35 sq km site. And shortly after the OSCE team arrived at the site on Monday afternoon, another 21 bodies were taken away on a coal-hauling truck.

The Dutch forensic specialist Van Vliet and several of his colleagues were the first foreign officials to come face to face with the sheer horror of the crash and its unseemly aftermath – about two-thirds of the passengers were Dutch citizens.

On the platform at Torez, they stood with heads bowed briefly, before donning latex gloves and requesting a torch before entering several of the corpse-filled wagons. Keeping to the theatre-of-the-absurd theme of the crash crisis, the first wagon was opened by a woman, thought to be a rail employee, dressed in a skin-tight, black skirt that shimmered in the sun, a body-hugging white shirt and striking wedge heels – with purple straps.

And at the end of a later tour of the crash scene, Van Vliet, said that seeing the remains of the aircraft strewn across the fields was an emotional experience, which, despite the summer heat, left him with goose bumps.

There was a sharp reminder yesterday that the aircraft did come down in a ‘hot’ war zone when fighting, believed to be between separatists and volunteer militia that fight alongside government forces, broke out in downtown Donetsk and near the city airport – five bystanders were killed.

SMH