An American geologist detained and tortured by China's state security agents over an oil industry database was jailed for eight years Monday in a troubling example of China's rough justice system and the way the U.S. government handles cases against its citizens.

Beijing's No. 1 Intermediate People's Court convicted Xue Feng of collecting intelligence and illegally providing state secrets and immediately sentenced him.

Xue's lawyer Tong Wei described the sentence as "very heavy", just short of the maximum 10 years, and said he would confer with Xue over whether to appeal. Xue was also fined 200,000 yuan ($30,000).

The U.S. Ambassador to China, Jon Huntsman, witnessed the sentencing in a show of high-level U.S. government concern about the case. Afterward, the U.S. Embassy released a statement saying it was dismayed and urged China to grant Xue "humanitarian release and immediately deport him."

For Xue, the verdict comes more than six months since the last court hearing and two and a half years after he was detained — a protracted prosecution and pretrial detention that Chinese officials never explained.

Born in China and trained at the University of Chicago, Xue ran afoul of the authorities for arranging the sale of a detailed commercial database on China's oil industry to IHS Energy, the energy consulting firm he worked for that is now known as IHS Inc. and based in Colorado.