The 39 people found dead in a lorry this week may have been victims of a Chinese “snakehead” gang, it is feared.

The gangs are known for smuggling people into other countries and are often thought to have links with Chinese organised crime groups known as triads.

Victims are reportedly typically targeted in the south-eastern coastal region of Fujian in China, and many are living in abject poverty, with hopes of travelling to wealthier western countries including the US, Australia and the UK.

They are usually required to pay thousands of pounds for the journey, and this can result in them building up large debts which then fall to their families to pay if they are unable to.

Snakehead gangs have been linked to the deaths of Chinese migrants in Dover in 2000, and Lancashire in 2004.

Edward Henry QC, a barrister at QEB Hollis Whiteman Chambers, told the PA news agency victims are “ruthlessly commoditised” and “no thought was given for their safety”, adding: “They are mortgaged for the rest of their lives. They pay so much to be smuggled.

“When they arrive they are often exploited.”

Henry, who has worked on several cases where there have been links to snakehead gangs, said one of their hallmarks was “extreme and indiscriminate violence” and they are part of an “international, complex network”, adding: “It’s a multi-national industry.”

He said they are often heavily involved in protection, vice and to some extent drugs, as well as the sex trade.

Mike Gradwell, a former detective superintendent who worked on the Morecambe Bay investigation, described snakehead gangs as “criminal travel agents”.

The gangs are said to tout their work in the streets as they hunt for victims with promises of better lives.

Some claim the victims are flown from China to Europe, where they are hidden among cargo in lorries, and driven without food, water, ventilation or toilets.

While some of the migrants make arrangements for the journey willingly, in the belief they will be able to make a better life for themselves in the UK, others become beholden to the traffickers and exploited for the sex trade and forced into labour.

Dr Winnie Wang, from a migration mobilities research institute at the University of Bristol, told PA there tends to be a hierarchy in the gangs.

She said: “People at the top are normally well-connected business people who invest and monitor the smuggling operation.

“They tend to be Chinese migrants themselves and live in destination countries.

“They often have already become permanent residents or naturalised citizens at the destinations.

“The lower level ‘snakeheads’ tend to be based in China, either living in the popular origins or nearby areas.

“They help to recruit migrants and collect money.

“There is a clear division of labour among the gangs and each person is responsible for a few specific tasks such as document forgery, transportation, etc.

“Surprisingly some snakeheads are well regarded among Fujianese communities.”

One of the most notorious gang leaders was Cheng Chui Ping, who became known as “the mother of all snakeheads”.

She is said to have been well-respected among the Fujianese in New York, despite her cruel crimes.

According to FBI archives, the New York shopkeeper was once seen as “one of the most powerful underworld figures” in the city.

Referred to also as Jing Ping Chen, she ran her operations from a shop in Manhattan’s Chinatown, where she was nicknamed “Sister Ping”.

She went to the US illegally from her home town, Fujian, in the 1980s and was thought to be actively involved in criminality from then until 2000.

She was jailed for 35 years in 2005 for money laundering and smuggling offences and died in prison in 2014.

The FBI described her crimes as “extensive and lucrative”, smuggling as many as 3,000 illegal immigrants from China to the US alone, making more than 40 million dollars (£31 million) in the process.

Using the money she launched a travel agency, owned restaurants, a clothing store and houses in the city, as well as property in Hong Kong and a farm in South Africa.

She was linked to the case of 58 Chinese migrants who suffocated in a sealed refrigeration truck on the way to Dover in June 2000.

Although described as the group’s ringleader, she escaped conviction but was instead jailed and fined for separate smuggling offences.

Snakehead gangs are also thought to have been involved in the Morecambe Bay cockling disaster in 2004.

Some 21 Chinese cockle pickers drowned in rising tides in Lancashire after being sent to gather shellfish. Two more were thought to have died but their bodies were not found.