A British corporate investigator embroiled in GlaxoSmithKline's Chinese corruption scandal has been sentenced to two-and-a-half years in prison for his part in a saga that has shone a light on the risks faced by foreign business people in China.

Peter Humphrey was convicted yesterday of illegally obtaining personal information on Chinese citizens, together with his American wife, Yu Yingzeng, who was jailed for two years. Mr Humphrey will be deported, although his wife will be allowed to remain in China after serving her prison term.

The pair were detained more than a year ago following work they did for GSK to help the UK drugmaker identify the source of a secretly filmed sex tape of its top executive in China in bed with his girlfriend.

The video – apparently intended to smear the executive – had been sent to Sir Andrew Witty, GSK chief executive, together with allegations of corruption by the company.

Mr Humphrey’s case was a lurid subplot to a broader scandal surrounding GSK, which was accused by Chinese authorities last year of funnelling billions of dollars in bribes to doctors and officials. – (Copyright The Financial Times Limited 2014)