VIENNA -- British actress Emma Thompson, Latino pop star Ricky Martin and Egypt's First Lady Suzanne Mubarak led international calls for an end to human trafficking at a UN forum on Wednesday.

The three were among guest speakers at the opening of a three-day anti-human trafficking conference, the first ever to be organized by the UN on what is estimated to be a multi-billion-dollar industry.

"When you look at the range of talent in this room, you would position UN.GIFT (the United Nations Global Initiative to Fight Human Trafficking) between Woodstock and Davos," said Antonio Maria Costa, director general of the United Nations Office on Drugs and Crime (UNODC) in his welcoming speech.

"Government statements, expert discussions, along with music, speeches, videos, films and art to inspire us all. I hope, by the end of the forum, a roadmap will be developed to guide us forward," Costa said.

And he continued: "This is not an inter-governmental conference, nor is it a talk shop. Think of it more as a rally. We march together."

Attending the event were around 1,200 experts, law enforcement teams, business leaders, NGO representatives and trafficking victims.

Human-trafficking is involved in a number of crimes, ranging from forced labor and sexual exploitation to the removal of organs and body parts.

According to UN estimates, around 2.5 million people are being trafficked around the world at any given time, and 80 percent of those are women and children.

The estimated global annual profits made from the exploitation of all trafficked force labor are $31.6 billion.

Puerto Rican pop star Martin, who has set up his own child welfare foundation, said that once he had become aware of the problem of human trafficking, he could not simply stand by and do nothing.

"Once I knew about it, I could not keep quiet," he said.

"I witnessed the horrors of human trafficking on a trip to India, where I saved three little girls from the streets of Calcutta. You have a problem. You know what was going on and if you won't do anything. You allow it to happen. With my foundation, I hope to ensure that every child has the right to be a child."

Accompanying the forum are a number of other events, including a film festival and a harrowing new art installation, which graphically depicts the terrifying ordeal of a woman sold into the sex trade.

The installation, entitled "Journey", was conceived by actress Emma Thompson in close collaboration with a Moldovan woman, named only as Elena, who was trafficked into the UK sex industry when she was just 18.

It comprises seven shipping containers which the spectator passes through, with each container depicting a particular stage of Elena's journey.

It ranges from her tiny home village in Moldova, via the frightening night-time lorry drive across Europe to the stinking, filthy, airless room in a London brothel, where she was incarcerated and forced to "service" as many as 40 men a day.

The room is indeed the most disturbing part of the exhibit, with its oppressive stench and squalor.

"Journey" already drew crowds of 15,000 when it was displayed in London's Trafalgar Square last year.