SAN JOSE (BLOOMBERG) - A Chinese professor was sentenced to 18 months in US prison after he was convicted of trade-secret theft and economic espionage, capping a seven-year prosecution.

Hao Zhang was charged in 2015 in a crackdown on Chinese theft of intellectual property that began under former President Barack Obama and has continued under the Trump administration with aggressive targeting of Chinese scientists and academics doing research in the US.

Five other Chinese citizens indicted alongside Zhang were never arrested.

Zhang was accused of conspiring with a colleague from the University of Southern California to steal and sell American secrets to the Chinese government and military through a shell company in the Cayman Islands.

US District Judge Edward Davila in San Jose, California, presided over Zhang's trial without a jury, where his lawyers put on what experts called a "damage control" defence that conceded key points in the government's case.

At a sentencing hearing on Monday, Davila ordered the professor to pay US$477,000 (S$650,000) in restitution to the victims of his theft - two small technology companies - and recommended he be sent to a minimum-security prison in California.

Daniel Olmos, one of Zhang's lawyers, declined to comment on the sentencing.