Australia's Prime Minister voiced deep concern on Monday, July 21, that pro-Russian armed men remained in control of the crash site of a Malaysian airliner shot down over Ukraine, saying the site looked more like a "garden clean-up" than a forensic investigation, Reuters reported.

At least 27 Australian passengers were among the 298 people aboard Malaysian Airlines Flight MH17, shot down over eastern Ukraine.

Prime Minister Tony Abbott, speaking on a breakfast radio show, said he had spoken "overnight" to Russian President Vladimir Putin for the first time about the disaster, amid mounting horror over the treatment of victims' remains.

"He said all the right things and now we need him to be as good as his word," Abbott told 2GB radio, declining to comment in detail about his discussion with Putin.

U.S. Secretary of State John Kerry on Sunday demanded Moscow take responsibility for the actions of pro-Russian militias whom Washington suspects of downing the jet with a missile. He expressed disgust at their "grotesque" mishandling of the bodies.

Moscow denies any involvement in the disaster and has blamed the Ukrainian military.

"Given the almost certain culpability of the Russian-backed rebels in the downing of the aircraft, having those people in control of the site is a little like leaving criminals in control of a crime scene," Abbott later told reporters, according to Reuters.

A 45-strong Australian investigation team was either in or heading to Kiev, but had so far been unable to travel to the site despite some improvement in access.

"There's still a hell of a long way to go before anyone could be satisfied with the way that site is being treated," Abbott said. "It's more like a garden clean-up than a forensic investigation. This is completely unacceptable."