Choo Chin-woo, a reporter with the leading newsweekly SisaIN, has been charged with violating the country’s election law. In their indictment, a copy of which was made available Sunday, the prosecutors said that through articles and a podcast a few weeks before the Dec. 19 presidential election, Mr. Choo “defamed” and “spread false information” about the president’s brother, Park Ji-man, with “an aim of blocking her election.” Mr. Choo attained nationwide fame when he worked as a co-host of the podcast “Naneun Ggomsuda,” or “I Am a Petty-Minded Creep.” Started in 2011, the online talk show became one of the world’s most downloaded political podcasts from the Apple iTunes store and raised allegations of wrongdoing against some of the country’s religious, economic and political leaders. The prosecutors’ attempt to arrest Mr. Choo follows earlier criminal indictments of television producers and Internet bloggers whose reports criticized the government on charges of spreading false information and defamation — a practice that international human rights groups have repeatedly denounced for creating a chilling effect among government critics. “My crime was raising questions those in power don’t like,” Mr. Choo, 39, said in a recent interview. “They hate me like a cockroach and want to squash me.” Filing a criminal indictment against people accused of spreading false rumors about public figures and then trying to incarcerate them during a long-term pretrial arrest is well beyond what would be accepted in other countries, said Park Kyung-sin, a professor of law at Korea University in Seoul. “It’s very unusual and against the international human rights standards,” he said. A Seoul court is scheduled to decide Tuesday whether to allow the prosecutors to arrest Mr. Choo. In his articles and podcast, the journalist revisited a little-known 2011 case in which Park Yong-chol, a son of a cousin of Ms. Park, was found brutally murdered in a mountain park in Seoul. The man’s cousin was also found dead, hanged from a tree. The police concluded that the first victim had been killed by the second, who then hanged himself. In his reports, Mr. Choo cited a legal dispute between the president’s brother, Park Ji-man, and his brother-in-law, who accused him of plotting to kill him by hiring Park Yong-chol as a hit man. (The brother-in-law, the husband of the president’s estranged younger sister, lost the case and served time in prison for slandering the president’s brother.) Mr. Choo’s articles raised questions about the police investigation and cited the suspicion raised by the brother-in-law and his lawyer that the murder of Park Yong-chol might have had to do with a plot to block him from testifying on their behalf in their legal battle against Park Ji-man. They also raised the possibility that the man who police said hanged himself might have been murdered as well. The president’s brother sued Mr. Choo on charges of spreading false rumors to influence the presidential election. Ms. Park’s office did not immediately respond to a request for comment. International free speech advocates — including Reporters Without Borders and Frank La Rue, the United Nations’ special rapporteur on the freedom of opinion and expression — have voiced concerns about a lack of tolerance for dissent in South Korea, where defamation is a criminal offense. Mr. Park, the Korea University law professor, said that one of the biggest problems with the judicial practices in South Korea was that they hampered public scrutiny and the role of media as a watchdog by placing the onus of proof in a defamation or false-rumor case not on prosecutors or those claiming to have been defamed but on the defendants, even when the alleged victims were public figures. In 2011, Chung Bong-ju, Mr. Choo’s colleague at the podcast, was thrown into prison for one year when he could not substantiate an allegation he had raised that former President Lee Myung-bak was involved in a stock fraud case. Many conservative South Koreans hated the co-hosts of the podcast, accusing them of irresponsible statements, character assassination and political cronyism passing itself off as satire. But they were wildly popular among young people who regarded the podcast as an alternative to the country’s mainstream media, which they considered pro-government and conservative. Although most of the allegations on the podcast were just that, some of them helped break the hottest news in South Korea. It was among the first to suspect the country's intelligence agency of involvement in a secret online campaign to try to discredit the opposition candidates in the December election. Last month, the police announced that at least two government intelligence agents had been involved in such an operation. Prosecutors have since expanded the investigation, raiding the headquarters of the spy agency. Prosecutors deny they were politically motivated when investigating government critics like Mr. Choo. But their detractors said that they were eager to press charges to show their loyalty to political power. “I don’t think this kind of thing can happen except in a backward country ruled by an authoritarian government bent on stifling freedom of expression," said Lee Jae-jeong, Mr. Choo’s defense lawyer, referring to prosecutors’ move to arrest Mr. Choo.