When a Thai smuggler was arrested in 2014 carrying 5 million baht ($190,000) in cash he was allegedly on his way to buy protected rosewood from a forest near Bangkok.
But the man's sister owned a zoo in north-east Thailand, and a counter-wildlife trafficking organisation had suspected there were links between the zoo and tiger trafficking from Malaysia and Thailand.
Thanks to that tipoff, a routine wildlife crime was exposed as something more sinister.
Thai authorities launched a financial investigation into the smuggler as well as the zoo's operations.
And when the Thai Anti-Money Laundering Office investigated the man's complex web of business connections and money transfers, they discovered he was behind a substantial racket to smuggle not only protected rosewood into China, but also elephant ivory and live pangolins.
It turned out the zoo had been used as a front for smuggling and money laundering.
From 2011 to 2014, it had laundered almost $45 million through a series of investments in property, jewellery and a car dealership.
The man was charged with trafficking, attempting to bribe officials and money laundering, and his sister was charged with money laundering.
Wildlife crime still viewed as 'emerging crime'
But Thailand's decision to "follow the money" is far from common practice in wildlife crime investigation.
A report has shown few countries recognise or investigate the links between wildlife crime and money laundering, even though such links are well known.
Wildlife crime has grown into a significant area of transnational organised crime, worth between $9 billion and $29 billion a year.
It threatens the existence of thousands of species of plants and animals, and affects almost every country in the world as a source, transit or destination for illegal products.
But a joint investigation by the Asia Pacific Group on Money Laundering and the UN Office of Drugs and Crime found despite an increase in large seizures of protected wildlife species and products, and the increased involvement of organised criminal groups, wildlife crime was too often viewed as an "emerging crime" or "outside of mainstream crime".
"Wildlife criminal cases very often start and end with the seizure, with limited investigation into the wider criminal network beyond the poacher or courier," the report said.
"Financial investigation and anti-money laundering techniques are rarely used in the fight against wildlife crime.
"As a result, there are major gaps in our understanding of the financial flows behind wildlife crime and inadequate measures are being undertaken to mitigate the risks of wildlife crime and associated money laundering."
Sophisticated methods on a par with drug crime
And yet, the level of sophistication of methods to conceal wildlife crime is increasingly on par with those used to conceal drug smuggling, the report said.
But many jurisdictions allocate far fewer resources to the detection and investigation of wildlife compared to drug trafficking.
For example, 86 per cent of jurisdictions surveyed — including Australia — were affected by wildlife crime, but more than two-thirds did not regard it as a significant money laundering threat.
Only 26 per cent carried out financial investigations into wildlife crimes, and only 1 per cent of all wildlife crime cases were reported to have involved money laundering investigation, charges or prosecutions.
The investigators found a widespread lack of political will to prioritise or manage wildlife crime on par with the scale and urgency of the issue.
"The failure of many jurisdictions to recognise these crimes as transnational organised crimes and to employ the full range of law enforcement tools available — particularly financial investigations — is a short sightedness for which we are paying a heavy price," the report said.
"The impacts of wildlife crime are significant and far-reaching, from the extinction of iconic species, to the loss of livelihoods of local communities, and threats to sustainable development, good governance, rule of law, and national security.
"Genuine and concerted international action is essential before it is too late."
Prostitutes were paid to pretend to kill rhinos
The report said transnational cooperation among law enforcement agencies could, and did, play a crucial role in detecting and disrupting the illicit financial flow from wildlife crime.
For example, in 2012 a South African court sentenced a Thai national to a record 40-year prison sentence for an elaborate fraud to smuggle rhinoceros horns to Asia after the animals were killed in "pseudo" hunts.
The man had taken advantage of the fact it was legal for foreigners to hunt rhinos in South Africa and ship the horns back home as personal trophies.
He had paid Thai prostitutes to visit game farms and fire a few shots with a rifle, then pose next to a rhino killed by someone else.
But a financial investigation involving law agencies in two continents showed the horns of 24 rhinos, instead of being sent home as trophies, had been sent to the owner of a wildlife trading firm in Laos.
The Thai man had signed a deal with the South African owner of a hunting reserve requesting the horns of another 50 rhinos, with an estimated street value of $25 million.
More often the investigators found financial investigation and anti-money laundering techniques were rarely used by authorities when tackling wildlife crime — and often investigations were done in isolation without cooperating with financial intelligence agencies.
The investigators have made a series of recommendations to improve the flow of information and cooperation between domestic and international law enforcement agencies, strengthen legislation and boost resources, as well as introduce stronger measures to identify, freeze, seize or repatriate assets and the proceeds of crime.