WARSAW (Reuters) - A Polish campaign group is suing an Argentine newspaper it says breached a new law that makes it a criminal offence to suggest Poland was complicit in the Holocaust.

In what appeared to be the first legal action under the so-called Holocaust law, just hours after it took effect, the Polish League Against Defamation said it filed a complaint against Argentina’s Pagina 12 daily. The paper said it had not received formal notice of the lawsuit.

A minister from Poland’s conservative government applauded the move to invoke the law which Warsaw says will protect it from slander, but which the United States and Israel said would suppress authentic historic research and free speech.

The League, a non-governmental group that campaigns to protect Poland’s historical reputation abroad, said that in December 2017 Pagina 12 used a photograph of Polish so-called ‘doomed soldiers’ who fought against communists after the war to illustrate an article on the Jedwabne pogrom of 1941 in which Nazi occupiers and local inhabitants colluded in the massacre of at least 340 Jews.

“The combination of these two threads: information about the crime on Jews in Jedwabne during the German occupation and the presentation of fallen soldiers of the independence underground is manipulation, an act to the detriment of the Polish nation,” the organization said in a statement.

The ruling Law and Justice party has praised the ‘doomed soldiers’. While many are seen as national heroes in the struggle against Soviet domination, some led killings of Jews, Belarusians and other minorities.

In an article posted on its website on Saturday evening, Pagina 12 said, “this newspaper did not receive any legal communication and only learned of the information through international news agency reports.”

“If successful, this attempt at international censorship could threaten freedom of expression worldwide,” the article read.

Deputy Justice Minister Michal Wojcik said he hoped the case would go to court.

“The organization has a right to submit such a notice. If the court decides the complaint is admissible - and it should do so -- then there will be a court case,” he told private radio station Zet.

Jews from across Europe were sent to be killed at death camps built and operated by Germans in occupied Poland -- home to Europe’s biggest Jewish community at the time -- including Auschwitz, Treblinka, Belzec and Sobibor.

Some 3 million Jews who lived in pre-war Poland were murdered by the Nazis, accounting for about half of all Jews killed in the Holocaust.

Thousands of Poles risked their lives to protect Jewish neighbors during the war. But research published since the fall of communism in 1989 showed that thousands also killed Jews or denounced those who hid them to the Nazi occupiers, challenging the national narrative that Poland was solely a victim.

According to figures from the U.S. Holocaust Memorial Museum, the Nazis, who invaded Poland in 1939, also killed at least 1.9 million non-Jewish Polish civilians.