JAKARTA, May 30: Five Chinese nationals, a Dutchman and a Frenchman who appealed against the length of their convictions on drug charges were sentenced to death by Indonesia’s Supreme Court on Wednesday.

A court spokesman said two Indonesians previously sentenced to death in the operation -- involving a drug factory capable of producing a million ecstasy pills a week -- had their sentences upheld.

Supreme Court spokesman Joko Sarwoko said the panel of judges hearing an appeal on Tuesday lodged by the syndicate described the drug operation as an act of international organised crime.

“They are experts in ecstasy production,” he said. “The Supreme Court decided to increase the sentence to death penalty.”

Dutch national Nicolaas Garnick, 61, and 43-year-old Frenchman Serge Areski had previously been jailed for life.

The five Chinese nationals sentenced to death -- Zhang Man Quan, 42; Cheng Kong Xin, 36; Jian Yu Xin, 37; Gan Chun Yi, 43; and Zhu Xu Xiong, 35, -- had previously received 20-year jail terms for working at the factory.

Officials said the operation was the largest in Southeast Asia and the third biggest in the world, capable of producing drugs with potential street value of $600 million a year.

The only legal step the group now has is to push for a judicial review if new evidence can be submitted or on technicalities.

A presidential pardon is also possible, but this would be extremely rare in drug cases.

Indonesia imposes the death sentence for many narcotic offences, defending the penalty as necessary to deter others in a country with a growing drugs menace.

Six young Australians were sentenced to death last year for heroin smuggling on Bali island—Reuters