The source, Igor Kalyapin, who heads the Committee Against Torture, an NGO, is in hot water for "allegedly divulging information from a preliminary investigation" into the incident, human rights group Agora said by e-mail.
In an article titled "Caucasian Hounds" (Kavkazkiye Borziye), published last September, Kalyapin said that in December 2009 riot police officers came to the Grozny home of Islam Umarpashayev, then 26, and arrested him because he wrote "unflattering things about Chechen policemen."
Kalyapin said officers brought the man to the precinct's basement, chained him up and threatened to kill him on trumped-up charges of being a rebel. Kalyapin said police in the region often arrest men who then "disappear."
The reporter, Svetlana Reiter, was questioned about how well she knew Kalyapin and whether she had seen any official documents about the Umarpashayev case. She replied that she had known Kalyapin since 2010 but only on a professional level, and she had not seen any official documents about the case.
She was also asked whether she had access to Kalyapin's work or personal e-mail address and whether Kalyapin had asked her to copy, publish or distribute any files sent by e-mail. Reiter said she had no access his e-mails and he didn't e-mail her any files.
The inquiry took place at the FSB headquarters at Lubyanka. Reiter went of her own volition. She was questioned by an investigator from the Investigative Committee's Nizhny Novgorod branch, which received Kalyapin's case from the North Caucasus department.
Nizhny Novgorod is where Kalyapin's NGO is based.
Founded in 2000, the Committee Against Torture has examined more than 1,400 rights abuse complaints and won millions of rubles in legal compensation to victims, its website says. On behalf of Umarpashayev, who is now a free man, the group has filed a complaint with the European Court of Human Rights.
On Friday, police and FSB officers attempted to search the NGO's Chechen branch but were not permitted to enter because they had no warrant. Last week, prosecutors, Justice Ministry officials and FSB officers raided the NGO's Nizhny Novgorod office.
Kalyapin faces up to three months in prison for the alleged information leak. In December, the Financial Times put Kalyapin on its list of "Russians to watch."
Sanoma Independent Media, which publishes Esquire, named "Caucasian Hounds" its best article in 2011. Sanoma also publishes The Moscow Times.