Passengers passing through Logan Airport in Boston are set to face a new layer of security, with the Transport Security Administration (TSA) introducing new ‘chat downs’.

Essentially a brief conversation with a specially trained agent, the measure has been adopted from Israeli security forces as a way of rooting out potentially dangerous passengers before they board aircraft.

Passengers will be asked a series of questions by a Behaviour Detection Officer (BDO) as they have their identification verified at the security checkpoint.

Based on physical cues or answers to questions during the dialogue, specially trained officers are able to detect suspicious behaviour, a TSA spokesman explained.

This analysis will help determine if a passenger should go through additional screening at the security checkpoint and identify “potentially high-risk travellers,” added a TSA statement.

However, looking nervous and averting eye contact are not considered to be giveaway signs, according to the TSA, which declined, however, to discuss what BDO officers would be looking for.

“Security officers are screening travellers for involuntary physical and physiological reactions that people exhibit in response to a fear of being discovered,” explained the TSA.

“We recognise an individual exhibiting some of these behaviours does not automatically mean a person has terrorist or criminal intent.

“Individuals exhibiting specific observable behaviours may be referred for additional screening at the checkpoint to include a handwanding, limited pat down and physical inspection of one’s carry-on baggage.”

However, the programme is causing controversy on Capital Hill.

Ranking member of the House Committee on Homeland Security Bennie Thompson called on the TSA to delay a new screening technique from being put into practice.

In a letter to TSA administrator John Pistole, Thompson said the “scientifically unproven technique” lacks “scientific validation, limited or comprehensive, of the efficacy of the Assessor model of screening to detect persons who pose a security risk to aviation”.

The programme will launch this week and is set to run for 60-days.