News presenter Kirill Kleimenov’s comments come as former spy Sergei Skripal and his daughter are fighting for their lives after being poisoned in what some consider to be a state-sanctioned “hit”.
He said: “I don’t wish death on anyone, but for purely educational purposes, I have a warning for anyone who dreams of such a career.
“The profession of a traitor is one of the most dangerous in the world.”
Mr Kleimenov said that few who had chosen the treacherous profession had lived to a ripe old age, the BBC reports.
The presenter added that excessive drinking, drug addiction, stress and depression leading to heart attacks and suicide were the “professional illness of a traitor”.
He said in an apparent threat, “traitors or those who simply hate their country in their free time, don’t choose Britain as a place to live”.
Mr Kleimenov added: “Something is wrong there. Maybe it’s the climate, but in recent years there have been too many strange incidents with grave outcomes there.”
The most bizarre aspect of the remarks is that it deviates from the official line taken by Russian state media.
The Kremlin has denied involvement in the alleged hit on Mr Skripal.
In previous instances where similar events have happened, the Russian media usually claims it is bemused that anyone should blame Moscow.
On state channel Rossiya 1, the presenter said the UK authorities “didn’t even try” to seek Russia’s cooperation in the investigation, “but have already discovered a Russian trace in the case”.
A report on Rossiya 24, another state channel, claimed the UK media is continuing to fan “anti-Russian hysteria,” and attempts to find a Kremlin link were not based on “facts, but purely on rumours and fabrication”.
The channel’s UK correspondence reported the “interesting detail” that the UK’s “secret” Porton Down facility near Salisbury manufacturers the VX and Sarin nerve agents – It is believed Mr Skripal was poisoned with a nerve agent.
Andrei Lugovoi, a suspect in the killing of former Russian security officer Alexander Litvinenko in London in 2006, dismissed talk of a “Russian trace” and said, “the English suffer from phobias”.
News websites widely reported the remarks of Mr Lugovi, who is now a member of Russian Parliament.
On Thursday the UK investigation into the poisoning of Sergei Skirpal, 66, and his daughter Yulia, 33, continued.
Officers have confirmed 21 people have been treated in hospital as a result of the attack.
It was previously claimed the number was “fewer than 10”.