Translation

真偽が疑わしい / 出所不明の / 作り話めいた

Meaning

Apocryphal describes a story, quote, or account whose truth or origin is doubtful, even if it is widely repeated. It does not simply mean old, mysterious, or interesting.

Examples

• その有名な引用は真偽が疑わしい。
  The famous quotation is probably apocryphal.
• 彼の子ども時代については、出所不明の逸話が多い。
  Many stories about his childhood are apocryphal.