GlaxoSmithKline PLC (LON:GSK) is under investigation for its “commercial practices” by the U.K.'s Serious Fraud Office, the pharmaceutical company said late Tuesday. The British company, which is already facing bribery charges in several countries, said in a statement that it plans to “cooperate fully with the SFO.”

“We are looking at possible patterns across numerous global jurisdictions. Media reports and developments in China have not triggered our announcement. We have been looking at this for some time and it’s coincidental that our investigation, which has been in the intelligence phase until now, has now moved to a formal investigation,” an SFO official, who did not want to be identified, told the South China Morning Post.

"Whistleblowers are valuable sources of information to the SFO in its cases," the SFO said in a statement, adding it welcomes "approaches from anyone with inside information on all our cases, including this one."

Earlier this month, Chinese authorities accused Mark Reilly, the former head of GSK's operations in China, and two other executives, of bribing government officials and hospital staff to use their products, resulting in $150 million in illegal revenue.

The company is also facing similar bribery allegations in Poland and Iraq. If the charges are found to be true, the company will be violating both the Bribery Act in the U.K. and the U.S. Foreign Corrupt Practices Act.