Re-issuance of OCI if one takes up another country's citizenship

Hi There - I'm Singapore citizen & have an OCI issued when I renounced my Indian citizenship. I'm planning to take apply for British Naturalisation (i've an UK ILR), once I do that I'll have to renounce SG citizenship as SG does not allow dual-citizenship.

So the question I've is do i need re-apply for an OCI or can I continue to use my current OCI?

Any advice is appreciated.

Thanks
Shail