BBC Business Editor Robert Peston has taken a "short leave of absence" after the death of his wife.
A note on his popular BBC blog read: "It is with great sadness that we can confirm that Robert Peston's beloved wife Sian Busby has passed away after a long illness. Our thoughts are with him and his family at this tragic time.
"Robert will take a short leave of absence from the BBC to return at a later date. We ask that you respect his and his family's privacy at this difficult time."
Ms Busby, a novelist, met Mr Peston when they were teenagers and they had a brief relationship, only to get back together years later.
In an interview with the Daily Telegraph Ms Busby, the author of historical thrillers, described the "scary" moment she was diagnosed with lung cancer.
She recently inadvertently featured on one of her husband's radio interviews when she was overheard by millions of listeners shouting goodbye to him while he was on the phone to the studio.
The couple have two sons.