The Vietnamese authorities have released and expelled one of the country’s most prominent dissidents, Nguyen Van Dai, and his assistant, Le Thu Ha.
The pair arrived in the German city of Frankfurt on Friday morning following their surprise release.
The move looks like an attempt by Hanoi to rid itself of one of its most determined and persistent critics and to ease pressure from Europe over its human rights record.
Mr Dai was sentenced to 15 years in prison in April, and Ha to nine years, on charges of attempting to overthrow the state.
They had been detained since December 2015 when they were arrested after attempting to hold a meeting with a delegation of EU politicians.
The government has said nothing about the circumstances of the deal, but it has exiled other prominent activists in similar fashion in recent years.
Mr Dai has in the past refused to trade his freedom for exile. During a previous period of imprisonment he was repeatedly approached by prison authorities who offered to release him if he agreed to asylum in the United States.
Vietnam has repeatedly set out to crush the spirit of Communist party critics with extended prison sentences, appalling prison conditions and extremely limited access to visitors, including family and supporters.
Mr Dai’s wife, Vu Minh Khanh, has led an international campaign to raise her husband’s profile overseas and persuade foreign governments to advocate for his release.
He is a founder member of the Brotherhood for Democracy, a beleaguered pressure group that advocates for more pluralistic government. He also acted as a human rights lawyer, before being debarred by the authorities, giving support to other dissidents and persecuted religious groups.
Mr Dai has close associations with Germany. He was working there at the time of German Unification, an experience that inspired him to work for democracy in his own country.
Vietnam may be hoping to defuse criticism from Berlin following the alleged involvement of Vietnamese agents in the abduction of a fugitive former oil executive last summer.
Germany expelled Vietnamese diplomats in response, leading to speculation that it could delay or derail ratification of a free trade agreement between Vietnam and the EU.