GENEVA: Former oil tycoon Mikhail Khodorkovsky, who was freed by Moscow last month after a decade in jail, vowed Sunday to fight for Russian political prisoners from his new base in Switzerland.

“You can’t live with peace of mind when you know there are political detainees rotting in prison,” Khodorkovsky told Swiss public television SRF on the train that took him from Berlin to Basel.

A spokeswoman for the man who was Russia’s most famous prisoner until his release on Dec. 20 said he had traveled to Switzerland with his wife to take their sons back to school.

“He is in Switzerland, where his children go to school,” she told AFP, refusing to reveal which city Khodorkovsky would travel to next.

SRF reported that the Kremlin critic arrived at the train station in Basel at 6:54 p.m. (1754 GMT) accompanied by his wife Inna, his daughter Nastia and twin sons Gleb and Ilja.

Bern said last Monday it had granted a three-month visa to the Kremlin critic, who was jailed for 10 years for financial crimes but last month pardoned by Russian President Vladimir Putin.

The 50-year-old had stayed in Germany since his release.

“Both of my youngest sons go to school in Switzerland, and their lessons will soon start up again,” he told SRF on the train.

It remains unclear where exactly in Switzerland Khodorkovsky’s wife and twin sons live, with a number of possible locations floated in the media in recent days.

The latest report in Swiss outlets suggested the family was based in Chernex, in the municipality of Montreux, overlooking Lake Geneva.

In a statement Sunday, Khodorkovsky’s spokespeople said he was “delighted that Switzerland is the second country in which he can breathe the air of freedom.”