Dutch-led investigators have released audio recordings that they say may implicate senior Russian government officials close to Vladimir Putin in the shootdown of Malaysian airlines flight MH17.

In an appeal for fresh witnesses released on Thursday, the five-country Joint Investigation Team said they wanted to know whether Vladislav Surkov, a senior advisor to Mr Putin, Sergei Shoigu, the Russian minister of defence, and Alexander Bortnikov, the head of the Federal Security Service, played a role in the disaster.

"The JIT is looking for information on the persons within the military and administrative hierarchy who enabled the shooting down of MH17 in Eastern Ukraine using a BUK TELAR," the JIT said in a statement accompanying the recordings.