Commission Regulation (EC) No 971/98 of 7 May 1998 initiating an investigation concerning the alleged circumvention of the anti-dumping duty imposed by Regulation (EEC) No 3433/91 on imports of gas-fuelled, non-refillable pocket flint lighters originating in the People's Republic of China by imports of the same lighters consigned from Hong Kong, Macao and Taiwan and by imports of certain disposable refillable pocket flint lighters originating in the People's Republic of China and making such imports subject to registration