The man, identified as Pawat Silamattakul, works as a tax adviser. He has already contacted London police.
The assault may have come from racism and prejudice against him, an Asian.
While local police are investigating, Thailand’s Foreign Ministry said it appreciated Pawat’s post warning Thais and other Asians to be aware of such a situation in Britain.
Cherdkiat added that if anyone experiences such an incident, he/she can contact the Thai Embassy, which has officers ready to offer immediate help.