|Supporters of Mikhail Khodorkovsky say his case is politically motivated [AFP]
Former Russian tycoon Mikhail Khodorkovsky has had his prison sentence extended to a total of 14 years, after being convicted of money laundering and embezzlement.
Judge Viktor Danilkin handed down the sentence on Thursday, following Khodorkovsky's second conviction.
Since his arrest in 2003, Khodorkovsky has already served seven years of an eight-year sentence for tax evasion, and the verdict means he is set to spend another six years in prison.
Danilkin told the court that Khodorkovsky and Platon Lebedev, his co-defendant, did not qualify for a suspended term.
Supporters of Khodorkovsky, the founder of Yukos, Russia's largest oil company, say the case is politically motivated. As evidence of their assertion, they cite his previous sponsorship of political rivals of Vladimir Putin, Russia's former president and current prime minister.
Analysts said the tough sentence is proof that Putin continues to dominate Russian politics, overriding President Dmitry Medvedev's more liberal stance on the trial.
"This confirms that Putin continues to rule Russia and that the liberal words of Medvedev do not mean a thing," Lilia Shevtsova of the Carnegie Moscow Center, said.
The verdict also comes amid foreign criticism, with US secretary of state Hillary Clinton and other Western leaders criticising the guilty verdict handed to the former billionaire businessman.
Another senior official in the administration of Barack Obama, the US president, said the sentencing will complicate Russia's bid to join the World Trade Organisation.
"It is not going to help their cause, it is only going to complicate their cause," the Reuters news agency cited the unnamed official as saying.
"The WTO is a rules based, rule of law organisation. Most countries around the world do not look at this verdict as a demonstration of the deepening of the rule of law in Russia. It will definitely have an effect on Russia's reputation."
Russia has fired back, saying that other governments should "mind their own business".
The two defendants, meanwhile, reacted calmly to the decision.
"You cannot count on the courts to protect you from government officials in Russia,'' Khodorkovsky said in a statement read outside the courthouse by his lead attorney.
But one woman, said to be Khodorkovsky's mother, shouted: "May you and your offspring be damned!" after the verdict was read.
"It's a cruel, shameful sentence which shows the absence of independent courts in Russia," Lyudmila Alexeyeva, one of Russia's top rights activists, told state media.
"An independent court would never have given such a verdict in this absurd case."
Al Jazeera's Neave Barker, reporting from the courthouse in Moscow, said that there was hope that a suspended sentence would be given.
"But that has now been dashed as this former tycoon is set to spend many more years in jail," he said.
Earlier this week, Judge Danilkin convicted the pair in their second trial on money laundering and embezzlement charges, a verdict condemned by the United States and other European countries as selective prosecution.
Prosecutors had asked for a sentence of 14 years for each of the pair in the new trial but also qualified this by saying it should run concurrently with the term handed to the former businessmen in their 2005 case.
Khodorkovsky has been in prison since being snatched off of his private jet by Russian security agents in October 2003 just as his dispute with Putin was becoming public.
He was later convicted on tax evasion and other charges and sentenced to serve time in a Siberian jail until 2011.
In the new trial, he is charged with embezzling 218 million tonnes of oil from Yukos between 1998 and 2003 and laundering $16bn.
Khodorkovsky's defence lawyers said the charges are absurd, since the amount of oil said to have been embezzled would be equivalent to the entire production of Yukos in that period.
"If they stole billions then I ask, where are those billions?" Boris, Khodorkovsky's father told reporters at the trial.
"Does he have anything of his own now, does he have personal property?"
Danilkin had earlier added to the string of other crimes attributed to the jailed tycoon by saying Khodorkovsky had broken the law by filing some of his financial reports in English only.
The verdict had been largely expected even before Putin used a national television broadcast to affirm that a "thief must be in jail".
Putin's aides later explained that he was only referring to the first trial and had no personal views about the second case.
But the defence team and many observers interpreted the comments as a direct order for the court to convict Khodorkovsky again.
Al Jazeera and agencies