JAKARTA (AFP) - Eight Taiwanese drug smugglers were sentenced to death by an Indonesian court Thursday (April 26) after being nabbed with around a tonne of crystal methamphetamine in a country that has some of the world's toughest anti-drug laws.

The men were arrested during raids last July, when the drug network's suspected leader was killed in a shootout with Indonesian police.

"The defendants have been found guilty beyond a reasonable doubt of colluding and smuggling narcotics," presiding judge Haruno Patriadi said as he passed sentence at the South Jakarta District Court.

Tipped off by their Taiwanese counterparts, Indonesian police said they discovered some 1,000 kilograms of crystal meth - shipped by boat from China - packed inside about 50 boxes. The haul was reportedly worth some US$144 million (S$191 million).

Some of the suspects were arrested at a beach where the drugs were delivered some 125 kilometres west of Jakarta, while others were apprehended in the suspected drug boat near Singaporean waters.

The sentence passed on the men - Liao Guan-Yu, Chen Wei-Cyuan, Hsu Yung-Li, Juang Jin Sheng, Sun Kuo Tai, Sun Chih-Feng, Kuo Chun Yuan, and Tsai Chih Hung - comes after 11 other Taiwanese drug smugglers were executed in Indonesia in recent years.

Indonesia has some of the world's toughest anti-drug laws, with sentences including the death penalty for smugglers who carry five or more grammes.

Several foreign and Indonesian nationals have been executed by firing squad in recent years for drug trafficking, including Australians Andrew Chan and Myuran Sukumaran in 2015, a case that sparked diplomatic outrage and a call to abolish the death penalty.