Police in Russia have launched a manhunt after a senior executive of the country's largest oil producer company, Lukoil, was kidnapped in the capital, Moscow.

I would describe this incident as the criminal world's invasion into Russia's big business

Oleg Morozov, Russian MP

Sergei Kukura - one of Lukoil's vice-presidents responsible for its finances - was on his way to work when his Mercedes was stopped by a group of masked men with Kalashnikov rifles, Lukoil said in a statement.

The attackers handcuffed his driver and bodyguard and drove Mr Kukura away in a car with blue number plates, usually used by police vehicles.

"Lukoil has not heard from the kidnappers and has no idea of the motive for the abduction," a company spokesman told the AFP news agency.

The BBC's James Schofield in Moscow says that while contract killing remains common in Russia, the kidnapping of such a senior official is unprecedented and is a blow to President Vladimir Putin's efforts to clean up the country's image.

Puzzling abduction

Mr Kukura, 48, was snatched early in the morning.

His car was stopped by the attackers at a level crossing not far from the Vnukovo airport on the pretext of checking documents.

Mr Kukura had access to "confidential information"

According to the company, the driver and the bodyguard - who were apparently drugged - woke up several hours later in their car, parked in a forest.

Mr Kukura, who has held his current post since 1996, is a top petroleum expert and had access to "confidential information, including state secrets," according to Lukoil.

As chief financial officer at Lukoil, Mr Kukura is a powerful figure and is said to be immensely rich.

But our correspondent says he maintains a low profile and is not involved in politics. He also plays no significant role in other businesses.

Russian businessmen have in the past been targeted by criminal groups, but experts such high-profile abductions are almost unheard of.

"I would describe this incident as the criminal world's invasion into Russia's big business," Russian lawmaker Oleg Morozov told the local news agency Interfax.

Shares dive

Officers from the Federal Security Service (FSB) have joined the manhunt and prosecutors opened a criminal inquiry.

Lukoil accounts for more than 20% of Russia's oil exports; the state owns about 14% of the company.

The news of the kidnap has immediately caused a sharp drop in the company share price on the Moscow stock exchange.