Henri Moureu, the scientist who pinpointed a string of V-2 rocket lauching sites from which the retreating Germans could have wiped out Paris in 1944, has died in Pau in Southwest France at age 79.

One of the least-sung heroes of the World War II, Mr. Moureu, a member of the French Academy of Sciences, was trained as a chemist and was a researcher on organic chemistry and nuclear physics for 20 years at the College de France. For nearly a quarter of a century he was director of the Municipal Laboratory in Paris, where he was a leader in combatting pollution in large cities.

A collaborator of the late Prof. Frederic Joliot-Curie, Mr. Moureu was given the difficult task in 1974 of keeping the French stocks of "heavy water," the essential ingredient for controlling nuclear fission, out of German hands.

Together with Prof. Jacques Trillat, another French Academy member, Mr. Moureu hid the heavy water in a cell at the prison at Rim from where it was taken to Bordeaux and later to Britain. The story was told in a French film entitled "The Battle of Heavy Water," directed by Rene Clement with a scenario by Jan Marin, a veteran of Gen. Charles de Gaule's exile government in London and former president of Agence France Presse, the French news agency.

The story is linked with the competition early in 1940 between the Allies and the Germans to obtain the production of the heavy water plant at Rjukan in then neutral Norway. In a skilful operations by the British Secret Service, the Germans were hoowinked and 185 liters of the factory's production were flown to Scotland and delivered to Moureu in Paris. Later, after the fall of France, it was returned to Britain.

The frustration of German plans to make an atom bomb is generally attributed to this and other clandestine allied operations during the war, including sabotage by the British. The sabotage also was carried out on the heavy water plant when Norway was occupied by the Germans.

Moureu's career combined theoretical physics and chemistry with practical application in both war and peace. His associates said Mr. Moureu had a passion for rocket propulsion and figured out the principle of the German V-2s when they were placed in operation.

His deductions about the size and appearance of Germany's final "secret" weapon enable him to help track down their bases. Particularly important was the pinpointing of the bases from which it was though the Germans planned to destroy Paris in September 1944.

The information was passed on to the U.S. Air Force, whose aircraft wiped out the launching sites.

Despite the importance of at least two of his wartime exploits, Mr. Moureu's name is barely known outside the world of science. Among his later activities were helping in defusing explosive devices and personally measuring the carbon dioxide production of factory chimneys.