The public trial of a foreign couple linked to GlaxoSmithKline plc (GSK) is set for August 8, a Shanghai court said yesterday.

Earlier this month, Chinese prosecutors accused British investigator Peter Humphrey and his American wife Yu Yingzeng for illegally obtaining private information. The couple were detained last year .

The couple will stand trial for “illegally obtaining private information about citizens”, according to the website of the Shanghai No.1 Intermediate People’s Court.

Two family friends said the trial was set for August 7 and would be closed to the public. But the official Xinhua news agency reported that the trial would be open to the public.

Courts in China are tightly controlled by the ruling Communist Party, and defendants are almost always convicted. Access to trials is extremely limited.

The case against Humphrey and his wife has become a key piece in a long-running investigation into GSK, whose China executives have been charged with orchestrating a widespread network of bribery to promote sales.

ChinaWhys, the risk consultancy run by the couple, was employed by GSK in April 2013 to investigate a former employee suspected of sending anonymous e-mails as well as e-mails containing allegations of widespread bribery at the British drugmaker.