Crimestoppers today calls on Independent readers to help them catch some of the country's most wanted human traffickers.

In the wake of the Independent and Evening Standard’s special investigation, the crime-fighting charity is stepping up the fight against modern slavery. Their "How to Spot The Signs" campaign launches today.

In particular, the Metropolitan Police want information relating to Mihai Negrescu, in connection with allegations of human trafficking for sexual exploitation.

Sarwar Mohammed Amhar, who allegedly kidnapped a 16-year-old boy (Sussex Police)

It is alleged that in July 2016, Negrescu recruited a female in Romania and offered her work in the UK catering industry. While in the UK, the victim was allegedly raped by Negrescu and then forced to work as a prostitute for his financial gain, being held at two different addresses in south-east London before she escaped and reported it to the police.

Negrescu, described as slim, between 25-30 and with dark cropped hair, is thought to have links to Romania, Italy and Germany.

"Modern slavery is a hidden harm," says Roger Critchell, Crimestoppers' director of operations. "People are reluctant to come forward and talk about it, either because they think that it's acceptable or because they're afraid of organised crime. We're only seeing the tip of the iceberg.

"There are other organisations offering support to victims. We are trying to help law enforcement, and it's vital that we raise awareness and get into hard-to-reach areas. That's where the Independent and Evening Standard investigation can be a big help."

In addition to Mr Negrescu, Crimestoppers would like information relating to Sarwar Mohammed Amhar, who allegedly kidnapped a 16-year-old boy, trafficked illegally into the UK, and held him against his will in Hastings. Amhar is described as a large male, aged 30-35, with a scar on his left arm.

"We need everyone to be working together to stop this," says Critchell. "We saw it before with sexual crime - that wasn't properly exposed until the police changed their ways. It's similar to where we are with modern slavery offences. It's starting to change, but we need everyone to know what to look for, and see the harm it brings. That gives us a better chance. Things will start to open up and we'll see more reporting."