A growing number of universities in Japan are introducing software systems to detect plagiarism in academic papers amid the evolving controversy over the "STAP cell" papers produced by Riken, the state-backed research institute.

Under an ordinance that took effect in April 2013, the education ministry has made it mandatory for all doctoral theses to be published on the Internet, replacing its decades-old rule requiring publication in print.

An official at a company selling plagiarism-checking systems said, "I believe more and more universities are introducing the system because if plagiarism comes to light after the theses are published, the credibility of the university's oversight will be called into question."