GlaxoSmithKline (GSK) is facing a criminal investigation in Poland over claims it bribed doctors to promote its lung drug Seretide. 13 people have been charged in connection with the probe launched by Polish prosecutors, according to Poland's Central Anti-Corruption Bureau (CBA) on Monday.The drugmaker said it was co-operating with the Polish authorities. One employee has been disciplined following an internal investigation into the allegations."The investigation found evidence of inappropriate communication in contravention of GSK policy by a single employee. The employee concerned was reprimanded and disciplined as a result," the company said in a statement."We continue to investigate these matters and are co-operating fully with the CBA (Poland's Central Anti-Corruption Bureau)."The news comes amid corruption allegations against the firm in China. In July authorities in the Asian nation accused GSK of funnelling up to 3bn yuan to doctors and officials to encourage them to use its medicines. Last week, the company said it was also investigating allegations of bribery in Iraq.Shares fell 0.61% to 13:47 on Monday.RD