From the AP:

In dozens of interviews with Sri Lankan officials, Western diplomats and former rebels, The Associated Press found that the Tigers raise US$200 million (€139 million) to US$300 million (€208 million) a year, mostly through extortion and fraud. They then use front companies or middlemen to buy arms from legitimate weapons makers in Europe and Asia. They move the weapons back to Sri Lanka on their own ships, all to continue their 24-year-long fight to create a homeland for the Tamil minority.