The Melbourne Cup could become part of an international money laundering scheme if Chechen dictator Ramzan Kadyrov's horse Mourilyan wins the race, an expert in Russian politics says.

Kadyrov has been described as the new Stalin and compared to Saddam Hussein and North Korean dictator Kim Jong-il because of the human rights abuses and murders he has allegedly perpetrated in Chechnya.

As the richest man in the former Soviet state, he has 99.9 per cent of the vote, a A$1 million ($1.26 million) watch, a gold-plated gun and a stable of horses based in Dubai.

South African trainer Herman Brown has brought Mourilyan out for today's Cup and if the highly fancied stayer gets up, the A$3.3 million prize money and the gold cup will be headed for Grozny, Chechnya's capital.

"It's a moral dilemma. If Kim Jong-il applies to have a horse run next time, what should we do?" said Australian National University academic Leonid Petrov.

"Perhaps there should be stricter criteria put forward for applicants.

"Kadyrov is implicated in many nasty things in Chechnya, in Russia and outside the borders of Russia. Personal enemies of Kadyrov die like flies in Russia and also in Dubai."

Russian security forces last week foiled an assassination attempt on Kadyrov, who thrives on the financial and political backing of the Kremlin.

"Lots of money has been pumped into Chechnya to prop up the regime of Kadyrov," Dr Petrov said.

"How much of this money has been used on his horses, we don't know but if the horse wins, the money will be the personal property of Ramzan Kadyrov.

"In that case it will become quite questionable whether the Melbourne Cup is participating in an international money laundering scheme."

Brown said he was aware of the controversy surrounding Kadyrov, whom he has met only once and communicates with through a government interpreter.

"I'm obviously aware of what people talk about," he said.

"I'm not really sure I'm the man to really talk about it. I'm just concentrating on the race.

"I don't know this [allegations against Kadyrov] for a fact. Maybe after the Cup, I'll investigate it."

British racing authorities are investigating Kadyrov and will rule in February whether to ban his horses from competing in the country.

If a British ban is enforced, he is likely to be shunned globally.

"Clearly we have to abide by the laws of whatever country we race in," Brown said.

- AAP