Mikhail Khodorkovsky has been reunited with his parents, a day after being released from a Russian prison and flown to Germany.
The former tycoon has been pardoned by the man he challenged – President Vladimir Putin – and freed from a decade-long sentence.
In what is believed to be his first television interview, Khodorkovsky has recalled tough jail conditions.
He said the only break he had was when his wife and other family members were allowed to see him for a few days.
“All the other times I was on a prison regime and, therefore, I had no long visits,” he said.
Putin’s decision to pardon Khodorkovsky has been widely seen as an effort to improve Russia’s image ahead of next year’s Winter Olympics in Sochi.
Khodorkovsky’s son, also in Berlin, has thanked his father’s supporters.
“As you can imagine my father is going through a lot right now and he cannot possibly be with all of you today,” said Pavel Khodorkovsky.
“But he really appreciates all of the support that he has received through these years and all of the people that have cared for him and cared for his story over the past 10 years.”
Khodorkovsky is due to give a news conference in Berlin on Sunday, at 1 p.m. Central European Time (CET), which will be live on euronews.