Research estimates there are fewer than 4,000 of the big cats left in the wild. A century ago there were around 80,000.
The crisis is blamed on poachers and trophy hunters. Economic development is also a major factor in their decline because it ruins their habitat.
Campaigner Martin Hughes-Games has been studying the tiger count in India, which accounts for 60% of those left.
He said: “India is a country that’s industrialising incredibly fast. There are roads and railway lines and industries everywhere you look.
“And of course human needs will always come before those of wildlife. So, the tiger populations are being isolated more and more.
“It’s becoming more difficult for the tiger to survive in this country. Poachers kill at least two every week.
“They use metal traps that skewer them through the mouth to leave them incapacitated.”
This method does not affect the fur, meaning poachers can make maximum profit from the kill.
There is demand from punters across China and South East Asia. Debbie Banks, from the Environmental Investigation Agency, said: “Almost every part of the tiger unfortunately has a value in the market.
“Skins are used as luxury home décor to put on the floor, on the wall and on the sofa.
“It’s a market that caters to those who want to show off their power, their wealth and their status.
“Tiger bone is used in medicine to treat rheumatism and arthritis, but it’s also used to make a wine as a general bone-strengthening tonic.
“Its teeth and claws are valued as jewellery items. Again non-essential, it’s all luxury. There’s absolutely no essential reason why a tiger body part should be traded.”
Experts have warned the number of tigers left in the wild could be even smaller than we think. Dr Yadvendradev Jhala thinks research could be unreliable.
He said: “The issue was that we had paper tigers, what you call political populations. Basically every country wants to say, ‘We are doing really well’.
“And every officer who manages a park wants to show that they’ve done their work really well.
“There was no way to count the animals with reasonable scientific information.” Work is being done around the world to protect the population.
At ZSL London Zoo is a Sumatran tiger, Asim. The species is the rarest and smallest subspecies of tiger on the planet.
They are currently classed as “critically endangered”. ZSL’s assistantx creator Teague Stubbington said: “It is estimated just 400 Sumatran tigers remain in the wild.
“Their survival depends on the sustained and continuing long-term effort of organisations such as ours.
“We’re working with the Indonesian government to train rangers working to prevent illegal wildlife crime and creating wildlife corridors for tigers to travel safely through their habitat.
“At ZSL London Zoo we also work with zoos across Europe. The breeding programme aims to safeguard the future of these incredible animals.”
A landmark documentary being shown this week will lift the lid on the crisis. ITV cameras were given access to India’s first-ever fully scientific tiger count.
It uses photo-technology, phone mapping apps and DNA analysis. The show follows Martin as he attempts to determine more accurate figures.
Tomorrow is International Tiger Day, which is held annually to raise awareness of conservation issues.