The threats began at the strike of noon, when Aleksey Krasovskiy, a Russian film director, started getting phone calls and messages about “Holiday,” a movie he was working on.

“Some men were waiting in the entrance to my old apartment building,” he said in a telephone interview. “Luckily, I had moved. That saved me.”

He said that one tidbit — that he was planning to make a comedy about the siege of Leningrad, a 900-day blockade of the city during World War II that led to the deaths of about one million civilians — was popping up repeatedly in calls and messages, as well as on blogs, in newspapers and on political television shows. Without having seen the movie, media outlets accused “Holiday” and Mr. Krasovskiy of mocking Russian history and dishonoring veterans.

Mr. Krasovskiy expected the harassment, which began in mid-October, to last only a couple of days, but it continued for more than a month. One Russian lawmaker said on Twitter that he hoped the film would never see the light of day and that he would do everything in his power to shut it down. A top official in United Russia, the party of President Vladimir V. Putin, said he would ask the culture minister not to grant the film a distribution license, according to Tass, a state news agency.