Macau crime boss, "Broken Tooth" Koi, was released from prison yesterday after serving nearly 15 years.

He was convicted of loan sharking, money laundering and being a gang leader in November 1999, a month before Portugal handed its long-time colony back to Beijing and the sleepy enclave became a country of modern resorts and a gambling mecca.

He had waged a brutal war against rival gangs for dominance of Macau's lucrative casinos. Authorities have warned hotels and casinos to tighten security and plan to keep a close eye on him.