German Foreign Minister Sigmar Gabriel told a news conference Friday that the alleged abduction in the German capitalwas "something that we will not…and cannot tolerate."

Germany says Vietnamese businessman Trinh Xuan Thanh was captured in July and speedily flown to Vietnam where he is facing charges of corruption and embezzlement - offenses that carry the death penalty. However, Hanoi insists the 51-year-old returned of his own volition.

Speaking in Wolfsburg, Gabriel told reporters the government was considering taking further steps against Vietnam after already ordering a Vietnamese intelligence officer based in Berlin to leave the country.

"We demanded that he leave because we strongly believe he is a person who was involved in kidnapping," Gabriel said. "Everything supports this assumption that he, with the help of the Vietnamese secret service and using his residence in the Vietnamese embassy in Germany, abducted a person who had asked for asylum."

"[Thanh] was taken out of Germany using methods which we believe one sees in thriller films about the Cold War," he added. "And this is something that we cannot accept."

Wanted man

Vietnamese officials had requested earlier this year that Germany extradite Thanh, who is accused of mismanagement at a subsidiary of the state-run oil giant PetroVietnam, resulting in losses of some $150 million (127 million euros). This week, Vietnamese police reported that he had handed himself in on Monday, following a 10-month manhunt.

But Thanh's lawyer in Berlin says that doesn't appear to have been the case at all. She told German newspaper Berliner Zeitung on Friday that she believed Thanh had been kidnapped and then transported via ambulance to a country in eastern Europe before being put on a plane to Vietnam. Witnesses also reported seeing armed men pushing Thanh and a female companion into a car outside the Sheraton hotel in Berlin's Tiergarten district. Both then appeared several days later in Hanoi.

Voluntary traveler?

Vietnamese state television on Thursday broadcast images of a tired-looking Thanh with tousled hair. He was quoted as saying he had returned voluntarily.

"I wasn't thinking maturely and decided to hide, and during that time, I realized I need to return to face the truth and ... admit my faults and apologize," he said in a prime-time bulletin on Vietnam Television.

The German government has accused the Vietnamese intelligence service of breaching international law, and has demanded that Thanh be allowed to fly back to Germany to claim asylum. He had been due to appear at a hearing about his asylum request on July 24 - the day after he disappeared.

Thanh was chairman of PetroVietnam Construction Joint Stock Corporation until 2013, when he was appointed to several senior government positions. He was elected to the National Assembly in May 2016, but was dismissed from the Communist-dominated legislature before its first session the following month.

nm/gsw (Reuters, AP, dpa)