NI contribution when working abroad

Hi, I am a UK tax resident working in Hong Kong for 6 months. My employer has no UK presence and I paid Mandatory Provident Fund (MPF) which is a kind of social security contribution in Hong Kong. Do I still need to pay national insurance or DCNI? I called HMRC to obtain a letter with employer PAYE reference. Do I need to do anything if I do not need to pay NI? Many thanks!

Hi walun,
Without looking at your personal records, We are  unable to confirm if you need to pay UK National Insurance contributions.
Direct Payment of National Insurance is subject to having full details of that individuals circumstances.
Therefore you will have to put your enquiry in writing, formally requesting a liability decision to whether you are exempt from paying UK NI.
You must provide all copies of certificates issued from the Hong Kong authorities advising that you are still insured with them. 
Provide full employment information including exact dates you are working in Hong Kong. 
The address to write to is:
HMRC
PT Operations 
International Caseworker
BX9 1AN
You may also find this link useful:
National Insurance if you work abroad
Thank you