According to Ukrainian publication Bihus.Info, a business owned by the 1988 Olympic pole vault champion and his brother Vasiliy Bubka has been supplying fuel to occupiers in DPR worth hundreds of thousands of Rubles.

The investigative report from Bihus.Info has claimed that the company named Mont Blanc exists in Russian and Ukrainian state register.

Fuel trading is the main activity of the firm, with Bubka reportedly carrying out deals on Russian tenders even after the invasion of Ukraine began in February last year.

An investigation against Bubka has been launched by Security Service of Ukraine since the information was made public.

"You have known me for a long time, you know my history, you know how long I have been involved in Ukrainian sports," Bubka said on his newly-launched YouTube channel with 15 subscribers.

"I was born on Ukrainian soil, I always represented Ukraine with great pride in the whole world.

"I have always fought for Ukraine, but now a campaign to destroy my reputation has begun against me.

"I, like every Ukrainian, made my choice from the very beginning - to be with Ukraine and to do everything possible in the fight against Russian aggression.

"I have not been to the occupied territories since 2014.

"I didn't visit my relatives and I wasn't even able to attend my mother's funeral this year.

"I have nothing to do with any business in the occupied territory."

Bubka, who appeared wearing a Ukrainian national team sweat shirt, pledged his loyalty to the country.

"My job is to support Ukrainian athletes and Ukrainian sports on the international stage," he said. 

"I am doing everything so that the current generation of Ukrainian athletes realizes their Olympic dream - to perform at the Olympic Games in Paris next year.

"To those who try to blacken my name, I would like to say that fighting for Ukraine in sports has always been an honour for me.

"Fighting for the state interests of my country is the highest honour for me."

Last September, Russian President Vladimir Putin signed documents to illegally annex the eastern Ukrainian regions of Luhansk, Donetsk, Zaporizhzhia and Kherson following disputed referendums.

The disputes between Russia and Ukraine over Donetsk dates back to April 2014.

In October last year, Bubka stood down as President of the National Olympic Committee of Ukraine after 17 years in charge.

He also stepped down from World Athletics last month, after insidethegames exclusively revealed that he would not stand for re-election.

Bubka oversaw the elections in Hungary as Britain's double Olympic 1500 metres gold medallist Sebastian Coe was re-elected as World Athletics President for a third and final term - his last act before bowing out after 22-years on the ruling Council of the governing body.

The 59-year-old has lived abroad since Ukraine was invaded and has faced criticism for not condemning the war.