For many years, Nepal has been widely regarded as a conservation success.
But now it is emerging as an international transit point for illegal wildlife goods, particularly those being moved between India and China.
Sandwiched between the two Asian giants, Nepal has devoted nearly 20% of its land to national parks and protected areas that have conserved endangered animal and plant species.
But outside such preserved areas, highways and mountain trails are increasingly becoming transit routes for wildlife traffickers, conservationists and officials say.
"The amount of wildlife goods seized in the recent past really tells us that Nepal is indeed a transit point," says Prasanna Yonjan of Wildlife Conservation Nepal, an organisation that has helped authorities catch many traffickers and poachers.
"We know Nepal is a conduit for the international market, particularly the Orient. Most of the goods seized here are not products from Nepal but from down south, particularly India, Bangladesh and perhaps also from Bhutan."
The superintendent of police, Devendra Subedi, who heads the crime branch in the capital, Kathmandu, says illegal wildlife trafficking has become a part of organised crime.
"There are several layers involved, and the people in it are found to be [involved] in other crimes like drug trafficking as well," he explains.
So much so that even the country's forest minister Matrika Prasad Yadav is well aware of the happenings. A former Maoist rebel leader, he even went on to say that several government agencies are involved in the trafficking network.
"One example is the smuggling of red sandalwood that comes in from India and is smuggled out to China," he said in an interview for the BBC's One Planet programme.
"I have documentary proof that even my own ministry, before I took over, allowed such smuggling by calling the red sandalwood 'common wood'.
"Later when my ministry, and the finance and home ministries, opened checkpoints on highways, my staff were harrassed and threatened by the people of the other two ministries.
"When tonnes and tonnes of red sandalwood can be smuggled in and out, you can imagine what could be happening with things much smaller in size."
But others point out that, as a former Maoist rebel, the minister has a track record of tough talk about other political parties.
Material that is much smaller in size, such as rhino horns, elephant tusks, and skin and bone from tigers and leopards, has been seized by authorities at different locations around the country, suggesting that they are indeed smuggled in and out.
In southern Nepal, just outside Chitwan National Park which has conserved endangered species like tigers and rhinos, is a government storage facility used for such seizures.
Hundreds of tiger and leopard pelts, their bones and claws, nearly 60 pairs of elephant tusks, more than 100 rhino horns and 50 sacks of shatoosh - the wool of the endangered Tibetan chiru antelope - are stored here.
The chief of the storage depot, Dhan Bahadur Thapa, said that every month at least three such products are seized from different places in the country.
"From the people involved in trafficking, we have come to know that such products are often sent to Bangkok, Hong Kong and China with the help of international smugglers," he said.
In most cases, the illegal wildlife goods were seized by chance, as there is no particular crackdown operation on traffickers.
One such seizure took place in Langtang to the north of Kathmandu in 2005. By pure chance, an army patrolling team came across nearly 240 leopard and tiger pelts being transported to Tibet.
Bhim KC, an official in the country's wildlife department, investigated the case and found that four of the five persons involved were Nepalese and one Tibetan.
"The Tibetan said he was only a porter carrying those illegal goods for another Tibetan who, he said, was an influential businessman in Tibet and Nepal," the government official explained.
Nepalgunj, a town in western Nepal bordering India, has been blacklisted by conservationists as one of the hotbeds of international smugglers.
The more than 1,800km-long border between Nepal and India is open, and Nepalese and Indians do not need passports to cross.
The district police office in Nepalgunj arrested five people on charges of trafficking tiger and leopard skins and bones in the last five years.
"These people were arrested from areas where we have our regular patrolling," said deputy superintendent of police Ram Govinda Pariyar.
"But, unfortunately, the border between Nepal and India is open and smugglers can come in from anywhere."
Wildlife officials have noticed that traffickers are indeed taking undue advantage of the open border.
"With the help of our informers, we have repeatedly confirmed that Nepalgunj is the trading centre of illegal wildlife, and this place also sees tiger bones from Rajasthan and Uttar Pradesh of India," said Ramesh Thapa, the assistant warden of Bardiya National Park which is near the border.
Conservationists say poaching has completely wiped out tigers in Siraska National Park in the Indian state of Rajasthan. A recent study showed that the total tiger population in India has declined from about 3,000 a few years ago to about 1,500 today.
A joint report from the UK's Environment Investigation Agency and the Wildlife Protection Society of India found that all tiger and most leopard skins reached Tibet and other Chinese provinces from India via Nepal.
"Most traders in Tibet, and Linxia and Gansu provinces, claimed to have connections in India and Nepal," stated the report of an investigation carried out between 2004 and 2006.
Conservationists and wildlife officials say illegal wildlife goods arriving from India were previously transported to trans-Himalayan regions such as Dolpa and Mugu before being smuggled out to Tibet through mountain trails.
Today, they say the regular route used by smugglers is the highway which ends in Kathmandu. From there, the goods are transported to Tibet.
"This route is much more convenient, because you can drive with the consignments all the way to the Nepal-China border," says Mr Thapa.
To find out how such illegal goods could be smuggled out through the regulated border, I travelled the Arniko highway that links Kathmandu with Tibet.
During the entire journey of nearly 100km, there was just one checkpoint. Police officials there said traffickers often used unregulated mountain trails to smuggle such prohibited goods across the border.
Ropes and pulleys
At the border point, known as Tatopani, customs and police officials refused to make any official comment.
But, requesting anonymity, some customs field staff told the BBC that at night, smugglers fix ropes at both sides of a rivulet that separates the Nepal-Tibet border. Then, with the help of a pulley, they smuggle items in and out.
WWF-Nepal's office in Kathmandu said it too had learnt about the rope and pulley idea.
"We have been trying to [raise] all these things with the Chinese side, but it has not been an easy experience trying to work together," said WWF official Diwakar Chapagain.
Just outside the Tatopani customs office, I saw for myself two impounded trucks with illegal cargoes of red sandalwood.
The vehicles had double-sided number plates. One side had a Chinese diplomatic number while the other carried a Nepalese registration.
The Chinese embassy in Kathmandu did not respond to a request for an interview.
Nepal's forest minister Matrika Prasad Yadav, whose Communist Party of Nepal (Maoist) has just won a major election, said his party will take action once it reaches office.
"If we come to power, all those who have been arrested as wildlife traders but who are actually only porters and the lowest strata in this trade will be released, and the real traders in the upper echelon will be arrested," he told the BBC before the polls.
There are allegations from conservation groups that the Maoists used illegal wildlife products to fund the insurgency, an allegation the former rebels reject.
The Maoists might like to take action against wildlife traffickers, but political and economic issues are likely to be more pressing factors as they try to lead a new coalition government.
You can listen to One Planet, or download it as a podcast, by visiting the BBC World Service's One Planet website . This edition should be available from approximately noon GMT Thursday