A number of people viewing the posts, written well before the Christchurch mosque attacks, contacted the Herald in disgust.
The posts are still online.
After the Herald approached the medical centre for comment yesterday morning, an internal investigation was launched.
In a statement, a spokeswoman from centre said management had met with the doctor and he had been immediately stood down from his responsibilities while an investigation into the matter was conducted.
"The only thing we are able to tell you at this time is that it appears that [the doctor] made these comments two years ago in response to an international incident," the spokesperson told the Herald.
The spokeswoman said the medical centre served a diverse community of patients and totally rejected any prejudicial sentiments.
"Given we are now conducting a thorough investigation we are unable to provide any further information at this time," the spokesperson said.
The Herald made several attempts to contact the doctor but was told he would not be commenting while the investigation was underway.