ZURICH, Nov 11 — Swiss researchers have found a new way of detecting renowned date-rape drug GHB in urine for up to 72 hours after ingestion, in a possible boon to sexual assault investigations.

The University of Zurich said in a statement published Tuesday that the newly discovered biomarker could “indicate earlier GHB intake even when the drug is no longer detectable using conventional analysis”.

“Every hour is critical when it comes to detecting the use of drugs used to render victims unconscious,” it said.

But GHB, which is commonly used for this purpose, including by being slipped into drinks of unsuspecting victims, is excreted rapidly from blood and urine, leaving little time to test for it before all traces vanish.