Supermassive black hole at heart of ancient galaxy ‘far larger than expected’
theguardian.com
theguardian.com
Other news articles (metro, yahoo) claim that it's 25 million LY distant (which can't be right, that's inside the MW).
I suspect that a single journalist has typoed 12.5 billion as 25 billion, and lots of others have scraped his article.
It seems to be conventional wisdom at any rate.