GlaxoSmithKline is sending senior internal auditors and lawyers to Shanghai as it steps up its own inquiries into allegations by the Chinese authorities of bribery by top staff.

The UK pharmaceutical group has hired accounting firm EY to conduct an independent review of its systems in China after police detained four senior local managers and banned a top British executive from leaving the country. The despatch of a team from its London headquarters comes as the company scrambles to co-operate with Chinese officials on their widening investigation and to strengthen its operations and management, thrown into turmoil in recent weeks.

GSK confirmed Steve Nechelput, its finance director in China, had been banned from foreign travel since the end of June. Mark Reilly, head of its commercial operations in the country, left Shanghai in early July and will remain in London helping with the investigation.