An art exhibit in Trafalgar Square highlighted the illegal sex trade
A London police unit dedicated to tackling human trafficking will close after the Home Office withdrew £2.3m funding support.
A Metropolitan Police spokesman confirmed the Human Trafficking Team will disband in April 2009.
Critics say the unit is vital to protecting vulnerable men, women and children who are sold or lured into the sex trade, slavery or illegal working.
But the Home Office said the money was intended as one-off start-up funding.
A Home Office spokesman said the government's support for the policing of those who traffic people into the UK for the sex trade or as low-cost illegal workers will continue.
"We have made it clear that trafficking should be core police business and a high priority, and the Home Office is continuing to support forces' effort, notably through funding the UK Human Trafficking Centre with £1.7m this year."
But in a statement, the Met said the dedicated team launched in March 2007 will have to cease operations because it does not have the money to keep it open.
This team has had some landmark cases and it is irresponsible to suddenly withdraw funds at this critical time
Christine Beddoe, children's rights advocate
"The Met does not have the additional funds to keep the team running in its current format whilst meeting other existing policing requirements."
Charities that attempt to rescue those trafficked into the UK against their will estimate that as many as 4,000 people are currently in the country as a result of being trafficked.
Many are used as slave labour or forced into prostitution.
Christine Beddoe, director of End Child Prostitution, Pornography and Trafficking UK (ECPAT UK) said the Met's unit is the only specialist one in the country and its mandate stretches beyond London.
"This is very distressing as this unit is not working only in London. London is the gateway for human trafficking.
"This team has had some landmark cases and it is irresponsible to suddenly withdraw funds at this critical time."
The news comes just a week after the human trafficking unit saw the successful prosecution of a gang of six men who trafficked young girls and women into the country and forced them into a life of abuse and prostitution.
One of the gang's victims was a 16-year-old Slovakian girl who told the court her harrowing story of being bought and sold several times, repeatedly raped and beaten.