Trafficking victims in India need more legal support to pursue cases against their perpetrators, while the country's police must understand that bonded and forced labour are also crimes, according to a report published on Wednesday.

The report by the Thomson Reuters Foundation and Freedom Fund said although illegal, trafficking is widespread across India while perpetrators go unpunished and many victims are unable to obtain justice and compensation.

India is home to more than 14 million victims of human trafficking, according to the 2014 Global Slavery Index, which found India had the greatest number of slaves of 167 countries.

Nick Grono, CEO of Freedom Fund, the world's first private donor fund dedicated to ending modern slavery, said human trafficking was a massively profitable business that needed to be "dealt with as a criminal enterprise".

Modern slavery is worth more than $150 billion a year in profits for human traffickers worldwide, according to the International Labour Organization.

"It means using the law effectively to challenge the economic model that supports slavery," Grono told the Thomson Reuters Foundation at the TrustWomen conference.

"If you can find effective approaches which make a difference in India, then you can also make a huge impact on the overall scale of the problem globally."

The report found that while hundreds of NGOs across India work on combating trafficking, only a few are able to pursue legal cases through to trial on behalf of victims.

This was due to funding restrictions, as money tends to be directed to non-legal victim assistance instead of legal work, longevity of cases, which can last for years, and the challenges of operating in an overstretched criminal justice system.

WHAT CONSTITUTES TRAFFICKING?

New anti-trafficking laws in India, ratified in May 2011, expanded the definition of trafficking and increased penalties, but confusion as to their interpretation and scope persists, the report said.

Several NGOs have said that while the new laws are being used for "traditional" trafficking offences, it is difficult to get police to register bonded labour cases or cases that do not involve movement of the victim.

"Historically, the Indian authorities have thought of trafficking only as sex trafficking, so it's important to broaden the definition to include forced labour, bonded labour, and children being forced to work in mines," Grono said.

The report also said that victims who press charges against perpetrators face harassment, violence and social stigma from their communities.

Citing the example of a 15-year-old Indian girl who was kidnapped, raped, and sold to a brothel, before escaping and filing a complaint with the help of an NGO, Grono said victims and officials "must realise the law is a powerful tool".

"If you enforce and reinforce the law, and have cases that succeed and set precedents, then you can change the mindset across the country," Grono said.

Among its recommendations, the report called for direct funding for NGOs to engage lawyers and pay for witness protection, expanded pro bono networks, and increased collaboration between anti-trafficking organisations.