A Vietnamese state oil executive who Germany says was kidnapped from a Berlin park in scenes reminiscent of the Cold War has withdrawn an appeal against a Hanoi court’s decision to imprison him for life, his lawyer told Reuters.

Vietnamese authorities have unleashed a sweeping crackdown on corruption that has seen a former politburo member and scores of other officials convicted and sent to prison.

Trinh Xuan Thanh, a former executive at a unit of state oil company PetroVietnam, had sought political asylum in Germany but returned to Vietnam in January and was sentenced to life in prison for violating state regulations and embezzlement.

“Thanh has decided to withdraw from the appeal trial starting today. He has also decided to withdraw from another appeal trial later this year,” Thanh’s lawyer, Nguyen Van Quynh, told Reuters by telephone.

In a letter to the appeal court on May 2, Thanh said he would not attend the trial because of “health conditions”, the Communist Party of Vietnam said on its website today.

But Thanh “doesn’t have any health issues”, Quynh, who said he had seen Thanh recently, told Reuters. He had cancelled his appeal because of a “sensitive issue”, Quynh said, without elaborating.

“The last time I saw him he was in good health,” Quynh said.

The foreign ministry did not immediately respond to a request from Reuters for comment.

Thanh was sentenced to life in prison for “embezzlement”, 14 years in prison for “economic management”, and fined several million dollars.

His case made global headlines last August when Germany accused Vietnam of kidnapping him in Berlin.

Last month, a 47-year-old Vietnamese man appeared in a German court accused of helping Vietnam‘s secret services to kidnap and repatriate Thanh.

Last week, Slovakia summoned the Vietnamese ambassador to relay its concern about media reports thatVietnamese agents used a Slovak government plane to secretly extradite him.

Thanh had been sentenced at the same time as Dinh La Thang, a former politburo member and chairman of PetroVietnam. Thang has gone ahead with his appeal trial, which is scheduled to last 10 days.

Vietnam offers amnesty to thousands of inmates a year, typically on national holidays, provided they have served at least a third of their sentences.

But a police source said Trinh Xuan Thanh was unlikely to be considered for amnesty until he paid his fine.