Washington, July 12 (IANS) A remote sensing technique could sniff out hidden explosives, chemical, biological agents and illegal drugs from afar.

The new system, using terahertz (THz) wave technology, can also "see through" clothing and packaging materials that might conceal explosives or other dangerous materials.

In the event of a chemical spill, for instance, remote sensing could identify the composition of the toxic mix. Since sensing is remote, no one will be harmed, reports Nature Photonics.

Terrorist threats have fuelled interest in developing THz remote sensing capabilities. Unlike x-rays, THz radiation poses little or no health threat, according to a statement of Rensselaer Polytechnic Institute.

Being portable, the technology could eventually be used to check out backpacks or luggage abandoned in an airport for explosives, other dangerous materials or for illegal drugs.

Xi-Cheng Zhang, director of the Centre for THz Research at Rensselaer Polytechnic Institute, who led the study, says the technique cannot detect materials that might be concealed in body cavities.

"Our technology would not work for owners of an African diamond mine who are interested in the system to stop workers from smuggling out diamonds by swallowing them," Zhang says.