A leading Nazi hunter has asked Denmark to investigate a 90-year-old Dane suspected of being involved in the mass murder of Jews in Belarus during World War II.

Ephraim Zuroff of the Simon Wiesenthal Center says he filed the request with the Copenhagen police Tuesday after the Justice Ministry turned down a similar request last year saying it was not their matter.

Zuroff told the AP they had a strong case against Helmuth Leif Rasmussen because of documents found by Danish historians published in a book last year.

The book claims that 1,400 Jews died in Belarus when Rasmussen, now known by the name Rasboel, was in the "inner circle" of the camp run by the SS.

Rasboel, who lives in Copenhagen, has acknowledged being a guard but denies killings.