President Dmitry Medvedev on Sunday urged Russia`s largest businesses to return "moral debts" and make sacrifices at a time of economic crisis, according to AFP.

"Nowhere in the world perhaps has the development of entrepreneurship in recent times happened as quickly as in our country," Medvedev said in a national television interview.

"People simply have been getting very rich in a very short time," he said. "Now it is time pay off debts, moral debts because the crisis is a test of maturity."

Medvedev said the current crisis, Russia`s worst economic collapse in a decade, was the time for the richest businessmen to embrace social responsibility and put interests of their employees before their own.

"If a person has really become a genuine businessman he can appreciate his employees," he said.

"He will perhaps try to put off part of his proposals, part of his ideas or personal consumption, save his staff, pay them salaries, save what he`s been doing in recent years."

Many of Russia`s richest people earned fortunes through controversial loans-for-shares privatisations in the 1990s and an economic bonanza fueled by high oil and gas prices gave birth to yet more tycoons.

Today Russia`s richest are struggling to pay off billions of dollars in debts built up in better times, while the government has said businesses should not assume there would be a blanket bailout of all.

"In this sense, this is probably cleanup time: he who survives the crisis conditions will be an effective entrepreneur, an effective manager in a good sense of the word," Medvedev said.

He acknowledged that the number of jobless in Russia has reached six million in what he said was a "complicated but so far controllable on the whole" situation.

Separately, Medvedev vowed to step up the fight against corruption, saying he will publicly declare his income starting this year and will urge other officials to do the same.

Medvedev said the law now required him to declare his income only when he ran for president.

"The fight against corruption is always a difficult systemic task," he added. "The fight against corruption in our country is a particularly difficult task, which will require colossal efforts, stamina."

The number of investigations into corruption allegations against public officials increased to 40,000 criminal cases last year from 2007, he said. Of those, 12,000 cases involved graft, he said.

"I hope a significant part of these criminal cases will be completed and result in a guilty verdict," he added.