China’s surging demand for luxury furniture and a revived cultural tradition are not only taking a toll on the forests of its Southeast Asian neighbors but also fueling a deadly crime wave across the region, according to an environmental monitoring group.

A new report by the London-based Environmental Investigation Agency says that illegal logging and corruption have contributed to the near extinction of Siamese rosewood (Dalbergia cochinchinensis), an increasingly rare tropical hardwood found in countries in the Mekong region, including Thailand, Vietnam, Laos and Cambodia.

Laws in these countries ban either logging or exporting the timber, but Chinese demand for the richly hued wood, known in Chinese as lao hongmu, literally “old redwood,” is so high that it is driving illegal logging and smuggling across the region, the report says, based on investigations over the past decade.

“From 2000-13, China imported a total of 3.5 million cubic meters of hongmu timber,” it says. “Nearly half of China’s hongmu imports since 2000 — amounting to 1,666,471 cubic meters valued at nearly $2.4 billion — came from the Mekong.”

Surveys in recent years found just up to 100,000 of the trees remaining in Thailand and very few in the neighboring countries.

The depleted forests are difficult to restore. They take “50 to 100 years before they are producing timber,” Jago Wadley, a senior forest campaigner with the Environmental Investigation Agency, said in an interview.

Beyond the biological toll, there is a human one, when illegal loggers encounter enforcement officers, the agency found.

“The tools of the trade are chainsaws, guns and even rocket-propelled grenade launchers,” the report said. “Since 2009, dozens of forest rangers have been killed” in Thailand in shootouts with loggers from remote villages or Cambodia, it continued. Forty-five Cambodian loggers were “reportedly shot dead by Thai forces in 2012 alone.”

As part of their work monitoring the trade, the agency’s undercover investigators met with traders who paid villagers from impoverished communities in cash or in methamphetamines to harvest the trees, and eventually sold the timber to dealers in China, often bribing government officials along the way, said Faith Doherty, a forest campaign team leader for the agency.

“Sometimes it can take us two to three years before we start to see a real picture emerging and who the actual actors are behind it,” Ms. Doherty said in an interview.

Trade data from the Chinese authorities and United Nations Comtrade, a United Nations-run trade database, was also used to piece together how remote forests in the Mekong area are being cut down to meet the “unprecedented” demand in China, Ms. Doherty said.

Rosewood has been highly prized for fine furniture in China since at least the Ming dynasty, about 600 years ago. But consumption did not reach the unsustainable levels noted in the agency’s report until recently, as the economic boom since the 1980s unleashed an appetite for luxury goods long suppressed under Mao Zedong.

“In the past 30 years, China went through twice as much of Asia’s Siamese rosewood resource as it did” over the five centuries of “the Ming and Qing dynasties combined,” said Yu Hongyan, a collector of rosewood furniture and timber living in Beijing. “Unfortunately, China’s history of furniture-making is essentially a history of forest depletion.”

The surge in consumption has sent prices skyrocketing. In 2011, investigators found a rosewood bed in Shanghai retailing for $1 million. Prices for fine rosewood furniture quadrupled in China in 2013, according to the Chinese Redwood Committee, an industry association. And it predicts a “steady rise in prices” in 2014, a forecast that so far appears on track.

Cultural tradition is not the sole driver of the bullish rosewood market. Speculation is also playing a role. Newly rich Chinese need a safe place to park their fortunes, Mr. Yu said. “The housing market and the stock market have not been strong,” he said. “People now invest in rosewood as an alternative to stocks.”

Siamese rosewood had been listed as “vulnerable” by the International Union for Conservation of Nature since 1998. Then, last year, the species was listed as “endangered” on Appendix II to the Convention on International Trade in Endangered Species, or Cites, banning all timber exports without a Cites permit.

However, the Cites ban only covers logs, sawed timber and veneers, a loophole in its enforcement that the Environmental Investigation Agency has urged Cites parties to close.

“The traders now can crudely process the timber in the source country and then export it as furniture, circumventing the ban,” Mr. Yu said.

Addressing the demand side of the trade, the agency’s report calls on China to halt imports of all rosewood from the Mekong region until the source countries produce evidence that any future exports will not threaten their Siamese rosewood populations and therefore are sustainable.

Meanwhile, Chinese consumers’ love for the rare hardwood appears undiminished.

“The Chinese used to talk about getting an armchair or a desk,” Mr. Yu said. “Now they talk about getting a rosewood armchair or a rosewood desk. The material has become a key factor in their purchasing decision. The consciousness of what makes something valuable has been transformed.”