Professors who taught dying tongue say university 'fabricated' claims.
Three academics who were sacked by a Japanese university on charges of "academic harassment" have claimed that they were ousted for attempting to teach an indigenous language.
The professors of educational linguistics, who have asked not to be named, are bringing legal action against Hokkaido University of Education after being fired by the institution in February.
Academic harassment - a relatively new concept in Japan - is defined as the abuse of power of one's academic position.
The university has accused the academics of "violating the human rights of the students under their supervision" by forcing them to work on an "extraordinary volume of assignments" for their own research purposes.
As a result, nine students suffered physical or psychological problems including hallucinations, the institution claimed.
Reports in the Japanese media have highlighted the fact that the three staff had chosen the indigenous language of Ainu as a theme for collaborative research for students majoring in English-language education.
The Ainu people are indigenous to northern Japan, where Hokkaido University is situated.
Historically marginalised, their language is now on the verge of extinction.
Recommendations made recently by a government committee to tackle discrimination of the Ainu people have been opposed by some conservative groups in Japan, which fear that the measures proposed could open the door to land claims and affirmative action.
At the time of their sacking, the three Hokkaido professors were teaching Ainu courses, with the approval of the university, and developing Japanese-Ainu dictionaries.
In 2007, two of the professors started constructing a database of books written in Ainu held by Japanese libraries, enlisting the help of student volunteers.
The professors said that while it was true that some students made complaints, the university "exploited these complaints and fabricated a story about harassment".
In a statement to Times Higher Education, they say the university accused them of "creating a cult group and engaging in mind control of the students".
The professors allege that their department head was told by a senior manager to stop them from teaching Ainu, a claim denied by the university.
After they were removed from their jobs, the Ainu language and culture classes they taught were scrapped, the professors say, adding that Japanese-Ainu dual-language signposts within the university have been taken down.
Yoshiya Goto, the university's executive director, denied that the teaching of the Ainu language had played any part in their dismissal and reiterated the allegation that the professors had "abused students' human rights".
He said: "Our resolution was not arbitrary but was based on a thorough investigation and followed the appropriate procedures. Their complaint is therefore entirely false."
He added that the professors had applied for an injunction against their dismissal at the Sapporo District Court, but their attempt had failed.