Singapore’s central narcotics bureau confirmed the execution in a statement, maintaining that Pannir, 38, was “accorded full due process under the law and was represented by legal counsel during trial and appeal”.

It said his six clemency petitions to the Singapore president were unsuccessful.

The bureau stressed that Singapore’s drug laws apply equally to all.

“In particular, foreigners who hope to make money off Singaporeans by importing or trafficking drugs in Singapore must face the consequences of breaking our laws,” it said.

It added that capital punishment is reserved for the most serious offences, noting that “the vast majority of Singaporeans support the death penalty for such crimes”.

Pannir was the second Malaysian to be put to death for a drug offence in the city-state in two weeks, after the execution of K Datchinamurthy, 39, on Sept 25.

He was convicted on June 27, 2017 by the Singapore High Court of trafficking in 51.84g of diamorphine at the Woodlands checkpoint on Sept 3, 2014, and was given the mandatory death penalty.

His appeal was dismissed by the Court of Appeal on Feb 9, 2018, and his clemency petition to the Singapore president was rejected.

On Sept 6, the Court of Appeal dismissed Pannir’s application for a stay of execution pending the outcome of disciplinary proceedings he had initiated with the Law Society against his former lawyer.

Just weeks before his execution, Pannir was interviewed by Malaysia’s narcotics crime investigation department, but both Malaysian and Singaporean authorities later confirmed that the information he provided had “no operational value”.

Two other Malaysians remain on death row in Singapore for drug offences – S Saminathan and R Lingkesvaran.