Ukrainian comic and presidential candidate Volodymyr Zelenskiy has denied any dependence on controversial oligarch Ihor Kolomoisky.

"I'm not interested in doing something if there is dishonest money or if I fulfill someone's will. Now they write a lot about my dependence on Kolomoisky. I don't have any agreements with him, signatures, or memorandums about the way I serve the owner Kolomoisky. He's not my boss. I don't have any boss," Zelenskiy said in a televised interview aired by the ICTV channel, controlled by powerful oligarch Viktor Pinchuk.

Zelenskiy added that the fact that almost all large TV channels in Ukraine belong to oligarchs "does not mean that all the people who work on these channels are not independent,” Interfax news agency quoted the comedian as saying.

Over the past days, Zelenskiy has been criticised by foreign journalists and independent observers due to the fact that the 1+1 television channel controlled by Kolomoisky has announced its intention to air round-the-clock programmes featuring Zelenskiy on March 30, the eve of the presidential election.

Last week, the US embassy in Ukraine unexpectedly said that its diplomats "are closely monitoring" developments surrounding the nation's largest lender by assets, PrivatBank, nationalised in late 2016. "Its nationalisation was a milestone in economic reform and the fight against corruption," the US embassy said on its official Twitter page, without providing any other details.

However, some experts and journalists in Kyiv are speculating that Zelenskiy is ready to de-nationalise the lender. The government nationalised PrivatBank, co-owned by Kolomoisky, in December 2016 after it failed to fulfil a three-year recapitalisation plan.

The bank was found to allegedly have a UAH148bn ($5.6bn) hole in its balance sheet because of related-party financing. In 2017, the then central bank governor Valeriya Gontareva said the post-nationalisation audit of the bank found that 100% of the corporate portfolio had been made to related parties.

Over the past years, Kolomoisky and another the bank's co-owner, Hennadiy Bogolyubov, have successfully defended themselves against Kyiv's legal attempts to recover the lost money.

Zelenskiy has strengthened his lead in the presidential elections, and now has nearly double the ratings of his rivals, according to the latest polls released on March 25.

Among decided voters, 27.7% will vote for Zelenskiy, compared to 16.6% for former prime minister Yulia Tymoshenko and 16.4% for incumbent President Petro Poroshenko, according to a poll conducted by the Rating Sociological Group of 15,000 respondents between March 5 and 14. In a second-round runoff, Zelenskiy would easily defeat either Poroshenko (39% vs. 18%) or Tymoshenko (34% vs. 21%), according to the poll.

Zelenskiy enjoys an even more commanding lead according to the results of a second poll, which was conducted by the Kyiv International institute of Sociology (KIIS) between March 14 and 22 among 2,004 respondents. The comedian has 32.1% support among decided voters, compared to 17.1% for Poroshenko and 12.5% for Tymoshenko. In the runoff, Zelenskiy would easily defeat Poroshenko (43.0% vs. 17.6%) and Tymoshenko (39.1% vs. 20.0%).