The National Drug Law Enforcement Agency said its search of the 62 containers in which 340 million tablets of Tramadol were found continued on Friday with the discovery of 11 new containers.
The 11 new containers were found to contain 241 million tablets of Tramadol, weighing 118 metric tons.
This brings to 581 million tablets of Tramadol so far discovered within two days of the search operations at Apapa sea port.
On the first day of the search operations, the NDLEA discovered 340 million tablets of tramadol from 12 containers.
The tablets, which are in various dosages ranging from 120 to 250 milligrams, are above the permissible threshold of 50 and 100 milligrams.
The suspected containers, all originating from India, have been on the watch-list of the NDLEA since November 2017 and have just been positioned for search by Nigeria Customs Service.
Out of 28 containers already positioned for search, 23 of the containers have been found to contain illicit Tramadol.
On Friday, no search of the containers took place.
It is expected that the search will continue on Monday.
There are 39 more containers to be searched, which the Agency strongly suspects to contain illicit Tramadol.
The Agency had in 2017 intercepted 160 million tablets of Tramadol at the Apapa Port, which ranged from 220 to 250 milligrams.
They were imported from India using false documents in the name of an unregistered company.