Apple says it is working to fix its speech-to-text tool after some social media users found that when they spoke the word "racist" into their iPhones it typed it out as "Trump."

The tech giant has suggested the issue with its Dictation service has been caused by a problem it has distinguishing between words with an "r" in them.

"We are aware of an issue with the speech recognition model that powers Dictation and we are rolling out a fix today," an Apple spokesperson said.

However an expert in speech recognition told the BBC this explanation was "just not plausible."

Peter Bell, professor of speech technology at the University of Edinburgh, said it was more likely that someone had altered the underlying software that the tool used.

A former Apple employee who worked on its AI assistant Siri told the New York Times: "This smells like a serious prank."