Sweden's former foreign minister says he helped an Afghan student and journalist secretly flee the country in 2009, which saved the man from a death penalty.

Carl Bildt says Sayed Pervez Kambaksh was convicted for publishing critical texts about Islam. He was smuggled into a Swedish government plane at Kabul airport while Bildt waited on board.

In an interview with Swedish daily Expressen, Bildt said the operation was coordinated with Kai Eide, the U.N.'s envoy to Afghanistan at the time.

Bildt said Kambaksh was pardoned after his escape and is now likely in the U.S.

He described the experience as "nerve-racking" for fear that Afghan security personnel would discover the plan.

Bildt tweeted Thursday that the operation was secret, but could now be revealed as all relevant leaders had changed.