A radical overhaul of airport security is needed, which will allow passengers to be screened depending on their perceived threat level, according to a leading expert.

Green Light managing director Philip Baum said that airports must implement a system of active positive profiling and reduce the number of crowds at check-in, which in turn create fresh risks.

“We need three lanes of security checks with perceived low-risk, medium-risk and high-risk passengers, who are those which we can’t easily identify why they would be travelling,” Baum said, speaking at Arena International’s Counter Terrorism and Security conference in London.

He also said that profiling is often viewed as discriminatory but this can be overcome with appropriate education of airport staff.

Baum, who provides training and consultancy at the UK-based firm, also warned against an over reliance on metal detectors, saying that none of the three plane hijacking incidents in the past month could have been prevented by metal detectors.