According to the Daily Telegraph, a public figure who was arrested said afterwards: "I have today answered bail following complaints I said were incredulous."
Was that a right or wrong use of incredulous?
The Oxford Dictionaries definition is "unwilling or unable to believe something" (an adjective, applied to a person or their manner).
Preliminary verdict: wrong, since complaints can't be unwilling or unable to believe something. It would be the public figure who was incredulous.
However, Merriam-Webster says it can also mean incredible: [this usage] "was revived in the 20th century after a couple of centuries of disuse. Although it is a sense with good literary precedent--among others Shakespeare used it--many people think it is a result of confusion with incredible, which is still the usual word in this sense."
The verdict: technically acceptable, but not the best choice. However, when you've just been arrested on serious charges, lapses of grammar are not your highest priority.
Also, incredible has its own problems. While the main definition is "impossible or difficult to believe," the meaning Oxford Dictionaries call informal ("very good, wonderful") is much more common these days and I'd wager the traditional meaning will have almost disappeared in another decade or so.
