Ephraim Zuroff, director of the Center's office in Israel, said the government officials have had plenty of opportunity to deal with the 86-year-old Kalejs in the past.
He made his comments on Jan. 24, just two days before a delegation including President Vaira Vike-Freiberga, Minister of Education and Science Maris Vitols, and Chief Rabbi Natan Barkan, traveled to Stockholm for an international forum on the Holocaust.
The two-day forum, from Jan. 26 to Jan. 28, which will be attended by representatives from 45 countries, aims to provoke discussion about the lessons of the Holocaust, pass on its testimony and give support to education and research.
Latvia's attendance at the forum comes when it has been accused of unwillingness to deal with its World War II past and the Konrads Kalejs issue.
The Wiesenthal Center discovered Kalejs, accused of killing tens of thousands of Jews as a commander with the Arajs Kommando, living in England in December.
Faced with potential deportation by the British government, the 86-year-old returned to Australia, where he retains citizenship.
Latvia's prosecutor general's office reopened its investigation into Kalejs in early January, although it found no evidence against him in 1997.
"This whole business of Latvia opening up a case is ridiculous because the investigation supposedly took place three years ago at our request when [Kalejs] was kicked out of Canada," said Zuroff.
Kalejs, who was deported from Canada in 1997 and from the United States in 1993, has been in the public eye for a long time, he said.
"The only serious chance there is for prosecution is if the Latvian government will make a very serious attempt to find and interview witnesses," said Zuroff. "And make it clear to them it is their obligation to testify against a fellow Latvian, if they have the information."
That information will not come from Holocaust survivors who are nearly impossible to find, he said, but from fellow war criminals or perpetrators.
"Past experience has shown that there is an extreme reluctance by perpetrators to testify in such cases. It's up to the Latvian government to change this attitude and conduct a serious investigation to make it clear that it is important to Latvia," said Zuroff.
On Jan. 19, President Vike-Freiberga emphasized her commitment to prosecute war criminals after a meeting of the National Security Council, attended by the Supreme Court and the prosecutor general's office.
"The president condemns war crimes, crimes against humanity, and genocide against the Jewish nation during World War II," said Vike-Freiberga in a press release.
"The president condemns all persons, who committed these crimes under subordination of the occupation regime of Nazi Germany, regardless whether they belong to the German, Latvian or any other nation."
She, like Prime Minister Andris Skele, said crimes against humanity have no lapse.
If there is evidence against people who participated in these crimes, and they remain unpunished, the president said, Latvia's legal institutions are obligated to enforce their criminal liability.
Zuroff said he knows where prosecutors can find that evidence.
"The key is to find the people who served with Kalejs. They hold the answer."