The German Foreign Ministry has given a second Vietnamese diplomat four weeks to leave the country because of "evidence that he was involved" in the kidnapping of former Vietnamese oil executive Trinh Xuan Thanh, spokesman Rainer Breul said on Friday.

After not receiving an "adequate response" from Vietnam, the Foreign Ministry posted on its Twitter account on Friday,  "We have therefore expelled another Vietnamese diplomat from Germany."

Germany expelled a Vietnamese intelligence officer in August for also allegedly being connected to the kidnapping, which German Foreign Minister Sigmar Gabriel said involved methods "one sees in thriller films about the Cold War." Czech authorities last month arrested and extradited a Vietnamese secret service agent, who is currently being held in Berlin.

The Foreign Ministry also said German officials had informed the Vietnamese ambassador that the strategic relationship between the two countries is temporarily on hold. Breul said Germany expects Vietnam to apologize for the incident, pledge not to repeat it and hold those responsible accountable.

Thanh, 51, was allegedly kidnapped by Vietnamese secret service in July. German media said the he had been taken in Berlin's Tiergarten park by several armed men. The Vietnamese businessman had sought asylum in Germany.

He is wanted on charges of financial mismanagement at a subsidiary of national oil and gas company Petro Vietnam that caused losses of around $150 million (€125 million). He is also facing an embezzlement charge related to real estate deals, which is punishable by the death penalty.

Vietnamese authorities have said Thanh handed himself over to police in his homeland in August.

dv/sms (AP, AFP, Reuters)