International Student with PhD stipend and foreign income

I would like to know the tax consequences of an international student doing doctoral research and being paid at UKRI rate from the respective university. Currently this rate is £18,622. Can this student earn money from foreign income as well? i.e. from his domicile country or from any other third country? What will be the tax consequence in this case?

Hi,
Please see the following guidance at:
Tax on foreign income
Tax treaties 
Your answer will depend on specific criteria being met.  We are unable to review personal matters in this forum.  
For an answer to a personal question of this nature, you would need to contact our self assesment helpline on 0300 200 3310 or contact our webchat facility at:
Contact HMRC
Thank you.