MOSCOW, RUSSIA — Russia's crime-fighting cat who was helping to stamp out the smuggling of sturgeon and salmon from the Caspian Sea has been run over and killed, perhaps the victim of a contract killing, media reported at the weekend.

Rusik, a former stray whose sniffer skills had reportedly led to several smugglers being collared, died under the wheels of a car which moved as he was about to detect some hidden salmon, the RIA Novosti news agency reported.

Rusik's sniffer skills led to several smugglers being collared.

Police at the check-point near Stepnovsky, in the Stavropol region bordering the Caspian where Rusik plied his trade, said the car driver appeared to have moved the car deliberately, although they did not rule out the possibility that he had simply not noticed the feline sleuth.

They adopted Rusik a year ago when, still just a kitten, he wandered into the local station and was found to have an uncanny ability to sniff out fish, notably the endangered sturgeon stowed away in trucks and cars on the way to lucrative markets in Moscow.

So effective was he at detecting smugglers that he soon put the local sniffer dog out of a job.

The report of his death comes only days after he came to the attention of the international media last Tuesday.

Russia is rife with smugglers trying to sell sturgeon and caviar at a massive mark-up.

Police at the Stepnovsky checkpoint said that they were deeply saddened by the death of Rusik but stressed that he had set a valuable precedent.

They are planning to train other cats to follow in his footsteps, RIA Novosti quoted them as saying.

Russia's Caspian region is rife with smugglers attempting to transport the sea's fish, including sturgeon and its roe known as caviar, to Moscow and other urban centres where it can be sold at a massive mark-up.

Around 95 per cent of the world's caviar comes from the Caspian, and Russian authorities are concerned that intensive smuggling risks driving the sturgeon to extinction.