Kiev, July 5 Ukrainian President Volodymyr Zelensky has been accused by his predecessor, Petro Poroshenkoy, of pursuing him in the courts out of a desire for "revenge".
When asked about election posters that were used by his campaign during last year's election, suggesting that a vote for Zelensky was effectively a vote for Russian President Vladimir Putin, Poroshenko told the BBC on Saturday that he had been proved right.
"I was one of the happiest (people) in the world if I was wrong," he said during the interview.
"But unfortunately this is true. The fifth column of the Russian federation are now playing a very important role in Ukraine."
Poroshenko told the BBC that his election defeat had led to pro-Russian figures returning to key posts in government.
For the past six years Kiev has been fighting a mostly low-level conflict against separatist forces backed by Russia in eastern Ukraine.
Poroshenko said that his successor was not "Putin's man", but that he was "inexperienced" and that there were now figures with Russian sympathies in his team.
The former leader currently faces more than 20 different investigations on what he says are politically-motivated charges.
The barrage of legal cases being filed against Poroshenko has brought statements of concern from Ukraine's Western allies.
When Zelensky's Prime Minister Denys Smyhal, was queried whether he was comfortable with the former President being targeted, he told the BBC: "I agree with you that it looks not so good.
"But I'm sure that everyone who did something bad, or violated the law, should be responsible for it."
( With inputs from IANS )