A Holocaust survivors group has asked the state attorney general to investigate the authenticity of a recently sold journal that a Stamford auction house owner says was written by Nazi war criminal Josef Mengele.

“The claim of this sale and the circumstances surrounding it should be investigated,” Elan Steinberg, vice president of the American Gathering of Jewish Holocaust Survivors and Their Descendants, wrote in an e-mail. “Where is this so-called diary? Who has even seen it and what sort of ‘expert’ authenticated it? Who is the mystery buyer who allegedly purchased it?”

Bill Panagopulos of Alexander Autographs said he sold the journal Tuesday for an undisclosed sum to the grandson of a survivor of the Auschwitz death camp, where Mengele conducted lethal experiments on inmates. The unidentified buyer planned to donate the journal to a Holocaust museum, Panagopulos said.

The Holocaust survivors group, Attorney General Richard Blumenthal wrote in an e-mail, is “understandably repulsed and shocked by the supposed sale