Tangaraju Suppiah, 46, was hanged at dawn on Wednesday over a plot to smuggle 1kg (35oz) of cannabis.

Activists said he had been convicted on weak evidence and received limited legal access during his prosecution.

But Singapore authorities said he had been given a fair trial and criticised those who questioned the courts.

Singapore has some of the world's toughest anti-drug laws. It argues these are a necessary deterrent to drug crime which is a major issue elsewhere across South-East Asia.

On Wednesday, Tangaraju Suppiah's family gathered at Changi Prison near the city's airport in the east to receive his body.

"The family said they weren't going to give up on him until right until to the end," anti-death penalty activist Kirsten Han told the BBC.

"They still have a lot of unresolved questions about his case, and the evidence against him. It has been such a harrowing experience for them."