Fictitious is used to describe something that is false or does not exist, although some people claim that it is true or exists.
We're interested in the source of these fictitious rumours.
我们对这些子虚乌有的谣言从何而来很感兴趣。
A fictitious character, thing, or event occurs in a story, play, or film but never really existed or happened.
fictional , imaginary
The persons and events portrayed in this production are fictitious.
这部作品描绘的那些人物和事件是虚构的。