JOIN USThe chemical arsenal which was uncovered recently follows the discovery of a deadly mustard gas cache in Libya, The Sun reported.
The country's new government called in international inspectors who found the chemical weapons.
"Gaddafi agreed to declare and dismantle all his weapons of mass destruction. Although we made real progress diminishing the threat he posed, in the last few days we have learnt that the new Libyan authorities have found chemical weapons that were kept hidden from the world," Cameron said at an event Monday night.
Gaddafi was killed in his hometown Sirte in October by forces of the rebel National Transitional Council.
He had earlier admitted to having 25 tonnes of mustard gas agent, 1,400 tonnes of other chemicals and 3,500 unfilled aerial bombs.