Sulim Yamadayev was shot early on Saturday in the underground car park of the Dubai apartment block where he lived. The murder was the sixth in a series of killings of Chechen exiles over the past year.
Kommersant said that according to local lawyers, investigators are viewing the case as a killing resulting from a drunken dispute, rather than a contract killing.
The relatives of those arrested said the men were not linked to security agencies or to Chechnya, the paper said.
The arrests of the Russians were conducted from Monday to Wednesday, with the last suspects detained at passport control when attempting to board a flight to Moscow.
Earlier reports said the gunman was described as a well-built, fair-haired man of between 30 and 40. Almost all the arrested men fit this description, the paper said.
Witnesses told the paper that one of the Russians was arrested on a beach and taken to a police station in only his swimming trunks.
Dubai police chief Maj. Gen. Dahi Khalfan Tamim earlier said that Yamadayev's killing had been organized and carried out by a criminal group.
Media reports said on Wednesday that Yamadayev had been buried at the Al Quoz cemetery in Dubai.
Yamadayev was officially dismissed from his post as commander of the Defense Ministry's Vostok battalion last August over alleged involvement in the 1998 abduction and murder of a Chechen businessman.
Sulim's brother, Ruslan Yamadayev, a former Russian lawmaker, was gunned down in central Moscow last September. He was a prominent opponent of Chechen President Ramzan Kadyrov, who has denied any involvement in the killing.
