'I believe that she died because she was drugged'. Picture: Vyacheslav Tebenkov

The unusual passenger was on board a train from Moscow bound for Novy Urengoy in northern Siberia. The nine month old cat was being taken from the Russian capital to the city of Surgut by a woman identified as Lyudmila Kosovskaya, 24.

Police in Ekaterinburg, 1400 km east of Moscow, said the owner lost control of the young lioness - which had been registered for travel as a 'domestic cat' - and 'could not cope with the situation and it was necessary to urgently isolate the animal which was running wild'.

A spokesman explained: 'The lion cub had first been kept in a cage but then the woman accompanying it for some reason let the animal out.

'When the animal, which was being transported without a muzzle, started behaving wildly, the woman couldn't control it. She shut it in her sleeper car and asked the train staff for help.'

The 'disheveled' woman begged the carriage conductor to shut the animal - which was out of its travelling cage - in the compartment.

The train supervisor became disturbed by the animal's growl from behind the door.

'It did not sound like a cat's meow', said one account. The owner admitted: 'It is a lion, but it is small, almost kitten'.

Walking on the train, the lioness struck a woman with its paw. The woman tried to calm the creature but angered it even more.

Fearful train staff alerted Yekaterinburg station and police were awaiting the train's arrival with veterinarians and local circus staff.

An eyewitnesses said: 'When the coupe was opened, we saw the lioness. She was not aggressive, but rather frightened with what happened. There was a cage, but the lioness was sitting on the bottom bunk.'

Unofficial sources claimed the animal was being taken to Surgut as a 'model', to use in a promotion at a local mall.

Yekaterinburg Circus spokeswoman Natalia Kazantseva said: 'Our trainer was on the scene. He helped to take the animal away from the train. It weighted 80 kilograms, not 50 as was reported.How could such a big animal be transported in such conditions? Nobody put her to sleep, she was given just a sedative medicine. She adamantly refused to leave the coupe. It was obvious that the lioness had been tamed, as she made contact with pleasure and ate meat from the hands.'

The owner meanwhile fled the train and is now being sought by police.

Witnesses said the lioness - worth an estimated 50,000 euro - was carried alive from the train, and it was later landed over to Mikhail Shutov, who heads a company which destroys unwanted dogs and cats.

'In the night we received a call: 'Please put asleep my restless lioness'. But we do not do that, we even do not have proper guns, so we asked for help.'

He claimed that he wanted to keep the lioness and find a home for the creature in a zoo or circus.

'I brought animal to my garage, but when I came in the morning to feed the lioness, she was already dead,' he said.

'I believe that she died because she was drugged. They could just pull her out of the train - and without these measures. Why was it necessary to inject her, she was still a child? I wanted to help, but everything turned out in the other way.'