KYIV, Oct 8 - Ukrainian prosecutors said on Friday they had widened an investigation into pro-Russian lawmaker Viktor Medvedchuk, accusing him of colluding with senior officials to finance separatist forces in the eastern Donbass region, Reuters reported.

In May, authorities put Medvedchuk, the Kremlin's most prominent ally in Ukraine, under formal suspicion of treason as part of a crackdown on his circle that has fuelled tensions between Kyiv and Moscow.