Just days after accusing the Dalai Lama of being a slave owner, China's ambassador to Canada is now calling the Tibetan spiritual leader a serial liar.

Lu Shumin also compared Tibet's government -- before the Chinese takeover in 1950 -- to Nazi Germany.

"The Dalai Lama has been telling lies to the world for decades," Lu told journalists at a news conference held Wednesday at the Chinese Embassy in Ottawa.

The statements were the latest in a series of attacks Lu has made about the Dalai Lama, a figure renowned by respected international dignitaries for his adherence to peace and non-violence.

On Monday, Lu told CTV Newsnet's Mike Duffy Live that the Dalai Lama was a slave owner, a claim rejected by a world authority on Chinese history. In an interview with CTV.ca on Tuesday, Timothy Brook, the principal of St. John's College, a graduate school at the University of British Columbia, warned the Chinese ambassador not to misrepresent history.

Brook said Lu's slavery claim was an outrageous statement coming from the representative of a country that is destroying the Tibetan people and their culture.

Tibet did have a system of bonded service in its past, but so did China and many other societies around the world, said Brook, noting that "these were not slaves on a plantation."

"If I were the ambassador, I would be very careful about using language like that. It is neither historically accurate, nor is it a way to deal with the current situation," he said.

But Lu went even further on Wednesday in what appears to be a concerted Chinese effort to tarnish the image of the Dalai Lama. He told reporters that a German visitor to Tibet in the mid-1930s found Tibet's system of governance quite similar to Nazi rule.

He also said Tibet was like "medieval Europe" before the Chinese takeover. Not referring specifically to Lu's latest vituperation, Brook noted that the ambassador's ventures into history bring forth little more than archaic and weak arguments.

"The ambassador really has a 19th century mentality, which is the civilizing mission. You civilize the barbarians," Brook said.

"If change needs to come to Tibet, it should come from the Tibetan people. It shouldn't come fom the Chinese people."

Brook noted that what is important is Tibet's recent history -- after China's takeover. He said the Chinese have forced Tibetans out of their homeland, brought ethnic Chinese into the region, and started a process which is about to destroy Tibetan culture altogether. He also said the Chinese are exploiting Tibet's natural resources at an unsustainable rate, drying out lakes, and creating "huge environmental problems."

Several world leaders have expressed concerns about Chinese suppression of human rights, especially in light of recent protests in Tibet, which turned deadly in mid-March. Chinese authorities violently suppressed demonstrations, and about 100 people appear to have died.

Lu accused the Dalai Lama of directly influencing demonstrators and violence, but gave no evidence.

The demonstrations and Lu's comments come as the world's attention is focused on China as it prepares to host the 2008 Olympic Games later this year. At least two European countries -- France and Belgium -- have suggested full or partial boycotts of the Games due to allegations of Chinese human rights abuses.

Lu said politics should be kept separate from the games.

"We certainly don't agree with politicizing the Olympics because it is against the Olympic spirit. I think most Canadian athletes will agree with me (on) that too and don't want to suffer and become a victim of a political game," he said.