A British investigator and his American wife were on Friday charged in China with illegally obtaining private information in a case that could provide details on the bribery probe against GlaxoSmithKline (GSK).Peter Humphrey and Yu Yingzeng, whose clients included GSK, were charged over a year after their arrest which coincided with a government investigation into allegations that the drugmaker had bribed local doctors and health officials to use their products.The couple is accused of illegally obtaining more than 200 items of private information, including household registration data, real estate documents and phone records, and then re-sold the data. GSK was not mentioned in the charge sheet but the couple's testimony will be closely watched to see if they provide any comments on the UK company, Reuters reported.A GSK spokesman has declined to comment on the trial.RD