Crime gangs are exploiting corruption at European borders to smuggle vast quantities of illicit goods, a new report warns.
The study examining the lucrative criminal trade in tobacco, alcohol and pharmaceuticals says corrupt officials are among several "key enablers".
They can undermine otherwise strict controls and allow the EU's outer defences to be easily breached by organised crime groups importing counterfeit or unlicensed goods, says the paper from security think-tank the Royal United Services Institute .
It says: "While some corrupt officials are prosecuted, there are reports of many more cases where corrupt officials were quietly transferred or dismissed and concerns that yet more remain undetected.
"The volume of illicit goods reaching EU markets would also seem to suggest that corruption is still a serious problem."
Corruption at the border can involve passing of information to criminals about patrol routes or customs checks or actively assisting in the safe passage of vehicles or shipments, omitting inspections and clearing them for entry, the report adds.
The assessment warns that numerous cases are believed to remain undetected, contributing to the substantial volumes of illicit tobacco, alcohol and pharmaceuticals that continue to evade detection and reach EU markets.
"Across the EU there are thousands of dedicated law enforcement professionals," the report concludes.
"However, until comprehensive and concerted action is undertaken, the corrupt minority will continue to undermine their work and, potentially, all other measures intended to prevent, detect or disrupt the activity of OCGs (organised crime groups) in the illicit trade."
It says illicit goods are arriving in "vast quantities" through EU ports, with counterfeit and pirated products estimated to cost economies around Europe tens of billions of pounds every year.
The report claims that free-trade zones are exploited by criminals who take advantage of limited oversight to re-document shipments and conceal their true origin.
Social media and the internet are also identified as an "enabler" for the sale of illicit goods, while the study says gangs are making increasing use of postal and courier systems.
The 18-month report involved field research in five EU member states - Greece, Italy, Poland, Romania and Spain.