The new allegations come after reports in 2017 of more than 100 gay men arrested and subjected to torture, and some of them killed, in the predominantly Muslim region in southern Russia.
The Associated Press and other media outlets have interviewed some of the victims, who spoke about torture at the hands of Chechen law enforcement officers. Chechen authorities have denied those accusations, and federal authorities conducted a probe into the earlier reports but said they found nothing to support the charges.
Alvi Karimov, a spokesman for Chechen leader Ramzan Kadyrov, told the Interfax news agency on Monday that the latest reports are "complete lies and don't have an ounce of truth in them." Karimov insisted that no one has been detained in Chechnya on suspicion of being gay.
But the Russian LGBT Network, which has been monitoring the situation in Chechnya and helping victims, said in a statement Monday that about 40 men and women have been detained on suspicion of being gay since December and that at least two of them have died of torture in detention. The detainees are believed held at the same facility that was named in the 2017 reports.
"Widespread detentions, torture and killings of gay people have resumed in Chechnya," Igor Kochetkov, program director at the Russian LGBT Network said. "Persecution of men and women suspected of being gay never stopped. It's only that its scale has been changing."
Kochetkov said the new wave of anti-gay persecution started at the end of the year, when Chechen authorities detained the administrator of a social media group popular with LGBT people in the North Caucasus. Kochetkov said the mass detentions began after the authorities got hold of the contacts on his phone.
LGBT activists in 2017 helped to evacuate around 150 gay men from Chechnya to help them restart their lives elsewhere in Russia. Many of them have sought asylum and resettled abroad.
"News that the authorities have resumed the crackdown is spine-chilling," said Marie Struthers, director of Amnesty International's Eastern Europe section. "With lives in jeopardy, there is an urgent need for an international response to protect gay and lesbian people in Chechnya."
Russian authorities have strenuously denied that killings and torture took place in the predominantly Muslim region where homosexuality is taboo, even after one man came forward to talk about the time he spent in detention in Chechnya.
Maxim Lapunov said he was detained by unidentified people on a street in the Chechen capital, Grozny, in 2017 and kept in custody for two weeks, where he was repeatedly beaten. He was let go after he signed a statement acknowledging that he was gay and was told he would be killed if he talked about his time in detention.
Lapunov, who is from Siberia, was the first to file a complaint with Russian authorities over the wave of arrests of gay people.
The Organization for Security and Cooperation in Europe last month called on Russia to investigate the reports and cited Lapunov's case specifically.
Kadyrov and his government in Chechnya have been accused of widespread human rights abuses against many dissidents, not just gay men.