TWO Jamaican nationals are being held in custody after gardai said they seized more than £50,000 worth of the drug "crack" cocaine in Dun Laoghaire at the weekend, writes Jim Cusack, Security Correspondent. It is the first sizeable seizure of the drug in this State and the consignment may have been destined for Britain. An estimated 400 grams of the drug was found by gardai at the ferry port on Friday night. The Jamaican couple were arrested and appeared in Dublin District Court. It is understood that the consignment arrived in Shannon Airport. According to UK Customs, the seizure was "reasonably sized".