Nigeria's drug enforcement agency on Sunday said it had arrested 22 Indian crew members of a merchant ship after 31.5 kilogrammes of cocaine was found on the vessel at Lagos's main port.

The seizure was made on January 2 aboard MV Aruna Hulya which "originated from Marshall Islands," Femi Babafemi, spokesperson for the National Drug Law Enforcement Agency (NDLEA), said in a statement.

The agency said in November that it arrested 20 Filipino sailors caught ferrying at least 20 kilogrammes of cocaine from Brazil to the same port.

Earlier that month, NDLEA said it was working with US and British anti-drug agencies to investigate a cartel behind the importation of 1,000 kilogrammes of cocaine discovered in a container at a Lagos port.