Leading flag states want to revive an ageing ship-tracking system as a key weapon against shadow fleets, despite new findings revealing major coverage gaps.

States, led by Liberia and Panama, have backed further investigation of long-range identification and tracking (LRIT) as a tool to eradicate the problem of vessels “going dark” to haul illicit cargoes.

LRIT was set up as a ship security system in response to the 11 September 2001 attacks on the US but has fallen out of favour with the coastal states that were supposed to benefit, partly because of its high cost.