The story goes that when Prince Baudouin took the oath to succeed his father after years of tumult over the monarchy, Communist leader Julien Lahaut shouted from the crowd: "Long Live the Republic!"

A week later, two men turned up at Lahaut's door in Belgium's coal and steel heartland and shot him four times with a Colt 45 revolver at point blank range. The killers sped away by car into the gathering darkness and were never caught.

If ever a murder had the hallmarks of a political assassination, the August 1950 slaying was it. But, who was behind it? And why? It's a murder mystery swallowed up in the fog of Cold War politics. Now, 62 years later, the Belgian government has approved fresh funds to solve the crime, convinced the moral implications echo down to this day.

The probe is part of a historical reckoning in which Belgium is revisiting several buried crimes, citing a "duty to remember." They include the involvement of authorities in the persecution of Jews during the Nazi era and government links to the assassination of Congolese prime minister Patrice Lumumba in 1961.

It's up to silver-haired historian Emmanuel Gerard to crack the Lahaut case.

One recent afternoon, Gerard pored over papers from 1950 found in the archive of a former interior minister. In uneven black-and-white typeface, a shadowy informer named Andre Moyen wrote to the former minister about the "execution" of Lahaut, dismissing the postwar Communist leader as "after all, an agent of the USSR."

A careful historian, Gerard says the missive in itself proves nothing. Yet it could be an indication that Belgian authorities, alarmed at signs of leftist foment in the country, might have known something about Lahaut's slaying and chose to keep silent.

In 1950, the Cold War was raging and fighting in Korea had just started. Belgium was bitterly divided between right and left over whether to welcome back from exile King Leopold III, who was long seen as having been too accommodating to Belgium's Nazi occupiers.

Amid the tensions, Leopold handed over power to his son Baudouin. The following week Lahaut was dead.

Historians have long suspected that rightwing pro-Leopold forces were behind the assassination — but that the government took little interest in solving the case because Lahaut was a Communist. In the political climate pitting the West against the Soviets, and with investigators not nearly as well-trained as those of today, the cold-blooded murder of the charismatic parliamentarian turned into a cold case.

Who fired the shots is not essential to Gerard and his team, nor to the politicians who have forced the murder back onto the public agenda. Now, it is more about who ordered the killing, and why the investigation never yielded results.

"It is not an issue of going after the culprits, they must be dead," said socialist senator Philippe Mahoux, one of those who pushed for the new inquiry. "But to know what really happened, that is fundamental."

"There must have been resistance in those days to let the truth emerge," he told The Associated Press in a telephone interview. "We have to know whether there were dark forces behind this ... If there is no solution it feels like a cover-up."

Despite clear political overtones, the case was treated as a common crime. A month after the killing, Communists were banned from all public functions as the Korean War made the Cold War even colder.

The case was officially shelved in 1972. Lahaut's murder turned increasingly into a half-forgotten historical oddity. Delving into the history of World War II and its Cold War aftermath was long difficult for a country struggling with memories of collaboration, postwar repression and anti-Communist action.

A prominent socialist European parliamentarian first took the lead in reviving the Lahaut probe by gathering some €40,000 ($52,000) in private sponsorship as of 2009 and followed by €150,000 ($194,000) in subsidies from authorities from Lahaut's French-speaking region in Belgium last year.

Then, over the summer, came €200,000 ($258,000) from the national government itself. All sources of financing bear a left-wing stamp. Government interest — and funding — has opened up since last year, when Elio Di Rupo became the first socialist prime minister in over 35 years.

"The fact that Di Rupo is there doesn't hurt to make sure things proceed," said Mahoux.

As a historian, Gerard stands above the political fray.

He's just happy he can keep digging.