Zaur Dadayev, the Chechen detainee charged with the assassination of Russian opposition leader Boris Nemtsov, has confessed that he was the sole actor behind the crime.

Dadayev said he plotted Nemtsov’s murder because of the liberal activist’s criticism of Islam and his support for the French satire newspaper Charlie Hebdo, Rosbalt news agency quoted a security source as saying.

“It’s concluded from his few confessions that he’s the sole organizer,” another source told Interfax, noting that “early reports point that Dadayev is the shooter of Nemtsov, but that can’t be 100 percent sure until we find the murder weapon”.

“Dadayev did confess to organising the crime,” a member of the police who is close to the investigation told Rosbalt, which he justified with Nemtsov’s constant criticism of Muslims living in Russia, the Prophet Mohamed, and Islam in general.

Russian authorities have enough evidence supporting Dadayev’s confession so “there’s no need to expect big revelations or arrests under the investigation”, the police source said.

After deciding that Nemtsov must be punished for his criticism of Islam, Dadayev called his two relatives, Anzor and Shagid Gubashev, who for a decade have lived in Moscow’s suburbs, who in turn involved two other Chechens in the crime, Ramzat Bakhayev and Tamerlan Eskerkhanov.

Dadayev, a former member of the Chechen Special Forces, revealed the details of the murder and informed about the involvement of the four other detainees.

Investigations found that the detainees read on the internet on February 27 that Nemtsov would be going to the Echo of Moscow radio station to contribute to a live programme.

Surveillance footage recovered from the exterior of the station showed that the murderers followed their target in a car, according to Rosbalt.

Nemstov was assassinated around 11:30 p.m. when he took four bullets to the back while walking with Ukrainian model Anna Duritskaya on a bridge in the middle of the Russian capital, just a stone’s throw away from the Kremlin.

After the bloody attack that targeted the Charlie Hebdo headquarters in Paris last January, Nemtsov expressed his support for the French satirist paper and justified their right to publish cartoons of the Prophet Mohamed.

He wrote on his blog, Echo of Moscow, that “Islam is still in the Middle Ages” and described the French massacre and jihadi terrorism as the “Islamic Inquisition”.