I am working on antiquated information then, I guess. I had heard that from someone who lived there for a while,quite a while ago.
The times I’ve seen the term used by Brits on their media referred back to nearly Georgian times and certainly no later than 1940. At that time, it generally meant Indians and Pakistanis. Times have changed I guess, especially as some of the most educated, literate and truly civilized people in Britain are of subcontintal origin.