In 2006 the drug related arrests had increased to 47,000 and 34,000 related to cannabis, the head of the Dangerous Drugs Control Board K Gamage said.
Drug related arrests usually increase when there is more supply, routine security checks are made and more manpower to conduct raids, he said.
Arrests are made on possession, transportation, usage and dealing of drugs.
Cannabis related had seen a 114 percent rise. Most of the rest is related to heroin.
Farmers in Sri Lanka's dry zone grow cannabis, though it is illegal. The drug is also used in traditional medicine.
Dealers transport the plant in dried form to the cities where there is greater demand.
People in the know say cannabis, particularly its dried flower can be bought from most wayside food shops in cities and truck stops on major roads because it is popular with long distance drivers.
Last year, authorities had seized 65 kilograms of heroin w