The document, titled "Covid-19 - Lessons from China," was reportedly sent by Bayer Vietnam's managing director, a Malaysian citizen of Chinese origin, to the company's department heads via email late last month.

Under the company's working procedures, the department heads would subsequently share the document with lower-level employees. The document aims to share China's success story in the fight against the coronavirus pandemic.

Vietnamese employees however protested the document after discovering that it included a map of China with the infamous nine-dash line, a demarcation line used by China to represent its illegal claims in the East Sea, known internationally as the South China Sea, violating Vietnam's sovereignty.

"We cannot accept having to share a document that contains the illegal image, especially when the company is operating in Vietnamese territory. Our nationalist spirit will not allow us to do it," a Bayer Vietnam employee told VnExpress.

A company representative said the document was shared with a small number of employees internally for the purpose of experience sharing in supporting the medical community within Asia. 

"The document was recalled immediately with actions taken to avoid any further communication. Bayer Vietnam deeply regrets what has happened over an image within a group internal document which drew attention from employees and the public," the rep added.

Inspectors from Ho Chi Minh City's Department of Information and Communications have reasserted that the circulation of maps containing the nine-dash line is a violation of Vietnamese law. They said the department had received reports of Bayer Vietnam's violation and will take follow-up action.

China's nine-dash line claims 90 percent of the 3.5-million-square-kilometer East Sea. The unilateral demarcation has been opposed strongly by the international community. Apart from violating Vietnam’s sovereignty, it overlaps with claims by Brunei, Malaysia, and the Philippines.

Bayer AG is a German multinational pharmaceutical and life sciences company operating in the fields of healthcare and agriculture. In Vietnam, the company has been present for over 25 years, employing about 700 people.