The reports of modern slavery cases were submitted to the UK's National Referral Mechanism (NRM), a national system in which individuals and charity groups identify suspected victims, who are later given a range of support such as legal aid and housing.
According to the National Society for the Prevention of Cruelty to Children, referred cases are fully investigated by trained professionals and officials with the UK Human Trafficking Center and the Home Office.
The NCA's annual report further noted that British citizens made up the largest number of referrals, with 1,625 reported cases. Albanian and Vietnamese nationals came in second and third, with 947 and 702 referrals, respectively.
"Of the 6,993 potential victims referred to the NRM in 2018, 52 were referred to Police Service of Northern Ireland for crime recording purposes, 228 were referred to Police Scotland and 251 to Welsh forces," reads the report. "The remaining 6,462 were referred to English police forces."
It adds that referrals involving minors, individuals aged 17 or younger, increased by 48% in 2018, noting that the spike in reports was largely the result of the "county lines criminal business model of exploiting vulnerable individuals and other forms of criminal labour exploitation."
The NCA explains that "county lines" is a phrase used to describe gangs that expand their business into smaller towns, driving out their competition and then using children and vulnerable persons to sell their products — generally drugs. Commonly sold drugs include heroin, cocaine and crack cocaine.
"Dealers will frequently target children and adults — often with mental health or addiction problems — to act as drug runners or move cash so they can stay under the radar of law enforcement," notes the government agency.
According to NCA Deputy Director Roy McComb, the increase in suspected modern slavery reports "is undoubtedly the result of greater awareness [and] understanding."
"That is something to be welcomed," he said. "However, the more we look, the more we find, and it is likely these figures represent only a snapshot of the true scale of slavery and trafficking in the UK."
"Modern slavery remains a high priority for law enforcement, with around 1,500 criminal investigations currently live in the UK. But we cannot stop modern slavery alone; we need support and assistance from across the public and private sectors, NGOs and most of all the public themselves," he added.
Per the Global Slavery Index, an estimated 136,000 people are living in modern slavery in the UK.
Most recently, three Romanian nationals living in the city of Birmingham were arrested on suspicion of modern slavery and human trafficking. According to Birmingham Live, two individuals caught up in the operation were enrolled into the NRM system.