Russian investigators point finger at Ukraine over downing of MH17

Dutch investigators and an Emergencies Ministry member work at the site where the downed Malaysia Airlines flight MH17 crashed, near the village of Hrabove (Grabovo) in Donetsk region, eastern Ukraine November 16, 2014. REUTERS/Maxim Zmeyev

MOSCOW (Reuters) - Russian federal investigators said on Wednesday they had testimony from a former Ukrainian air force mechanic supporting a Moscow theory that a Malaysian passenger plane downed in east Ukraine last summer was attacked by a Ukrainian fighter jet.

Moscow has stepped up a campaign denying any responsibility for the downing of the airliner on July 17, 2014, with the loss of all 298 people aboard. Several versions presented by various Russian officials, however, are contradictory.