Criminals are exploiting the migration crisis to dramatically increase the trafficking of Nigerian women and girls into Europe - and many could end up being exploited in the UK, the independent anti-slavery commissioner has warned.

Kevin Hyland said Britain has a responsibility to act and called for an immediate response to the crisis before it worsens.

There are up to 13,000 victims of modern slavery in the UK, according to Government estimates. Nigeria has consistently been one of the top countries of origin among victims identified here, Mr Hyland said.

Separate figures indicate that 5,633 Nigerian women and girls reached Italy by sea last year - nearly four times the level recorded in 2014. Estimates suggest that close to four in five are trafficking victims who criminals plan to force into the sex industry across Europe.

Mr Hyland said: " Simply put, this is now one of world's major human trafficking crises. It has been going on for a number of years, and a failure to act has allowed the criminals to take advantage of the current migration crisis.

"The rise in the numbers is staggering. Nigerian women and girls are enslaved and sexually exploited here in the UK. We must act now."

Last month Prime Minister Theresa May announced a new £33 million International Modern Slavery Fund. Mr Hyland argued preventing trafficking from Nigeria at source must be one its core focuses.

Describing Edo State in the south of Nigeria as the country's "trafficking hub", the former Metropolitan Police detective said: "U nless we bring focus to this region, criminals will simply continue to move huge numbers of women and young girls into Europe to be exploited and profited from, as if they were a mere commodity."

Gangs are feared to be targeting women and girls and deceiving them with promises of a life of opportunity in Europe.

Mr Hyland added: "These vulnerable people, many of whom are young girls, have no understanding of the conditions under which they will 'work', the violence and threats they will receive, the size of the debt they will incur and the brutal exploitation they will suffer.

"The bait is taken, and so too is their freedom. This needs to stop. These victims are exploited here in the UK and we have a responsibility to act.

"I have visited some of the local rural communities targeted by the traffickers. Often the young people there are very vulnerable to deception. But many of the community leaders do want to act to stop this trade, and we should help them."