Mr. Van Damme was arrested at Singapore airport in September 1991 after the police found 9.5 pounds of heroin hidden in his suitcase. He was taken into custody shortly after he arrived from Thailand, a major shipment point for narcotics, in transit to a flight to Athens.

Mr. Van Damme, a resident of Nigeria since 1976, said that he had been set up by a Nigerian criminal operation that he had exposed to the Dutch intelligence agency.

His assertion of innocence seemed to gain some credibility after the Dutch Foreign Ministry confirmed earlier this month that Mr. Van Damme had been in contact with the intelligence agency just before his arrest in Singapore. The exact nature of those contacts was not disclosed, however, and Dutch officials said they did not directly involve the drug charges in Singapore.

Mr. Van Damme, who was married to a Nigerian, said that he had been carrying the bag for a Nigerian engineer, and that he had not known what was inside. Nigerian drug operations reportedly control much of the heroin trafficking in Southeast Asia.

Singapore has executed scores of people, including many foreigners from other Asian countries, under a 1975 drug law that mandates capital punishment for possession of as little as a half an ounce of heroin.