The tragedy of the 39 people who died in the back of a lorry in Essex has brought the whole issue of modern slavery to the forefront.

The prevalence of slavery in 21st Century Britain is an often hidden problem but nonetheless continues to grow.

The Metropolitan Police reported 263 cases of modern slavery in London last year. The Global Slavery Index estimate that there are more than 130,000 people living in modern slavery in Britain today.

A number of sectors seem to attract slave labour. They include car washes, nail bars, construction, agriculture and factories, domestic service, catering and the sex industry.

A number of the pitiful tales of how people have been trafficked to the UK, then effectively sold into slavery, have been exposed.

Shayne Tyler, the compliance director at vegetable suppliers Fresca Group, is a passionate campaigner against modern slavery.

He has come across all sorts of different forms of enslavement that come up in the supply chain of an international company.

His advice is to be vigilant, questioning suppliers about their processes. If goods are too cheap then there is every chance that some sort of malpractice is going on along the line. Shayne suggests that we should all become more pro-active, asking supermarkets about the processes that bring these products to the shelves.

Car washes are places where slave labour can be found. If a car wash is too cheap - £5 or less - then the people working there are not likely to be being paid very much - if anything at all.

The Church of England has an app where people can file a report if they suspect some form of slavery is going on at a car wash.

There is also the Modern Slavery Helpline, when people can get in touch if they suspect something is wrong.

While people are becoming more knowledgeable about the existence of modern slavery, there is still the problem that once many of those caught up in this insidious business are freed, they later return to slavery.

Mark English, human trafficking and organised crime co-ordinator for Norfolk, explained that once freed people can then be relocated to another area of the country, where they can be isolated. If there are none of their community around them, individuals feel vulnerable, so they can once again be in danger of falling back into slavery.

There may also be the threats from traffickers as to what could happen to relatives back in the country from which they have been trafficked.

So there is much to do. If an individual, once liberated, is to remain free then paths need to be developed that give the support to ensure that they do not fall back into slavery again.

Slavery is horrendous. It is incredible that it continues to flourish in this country in the 21st Century. A concerted effort is required across the country to eradicate this appalling exploitative business from continuing to prey on vulnerable people. Events in Essex with the appalling loss of life should act as a wake up call to us all regarding the human cost of this modern scourge.