Malaysia has launched an investigation to uncover how hundreds of migrant workers arrived from South Asia without jobs, despite having paid steep fees to get employment, officials and rights groups said.

The issue revives concerns over labour abuses in Malaysia, a key manufacturing hub at the heart of the global supply chain that has faced several accusations in recent years over exploitation of workers.

Hundreds of workers from Bangladesh and Nepal have arrived since December after paying up to 20,000 ringgit ($4,500) to middlemen to get employment, officials of two rights groups who interviewed dozens of the workers told Reuters.

Many took loans to pay recruitment fees, but are unable to start repaying them without jobs or salaries, the activists said, adding that on arrival, their passports had been taken away by recruitment agents...

The Malaysian government is investigating the matter, said Asri Rahman, the director general of its labour department, but declined to provide details until completion of the inquiry...

He described as "appalling" the crowded accommodation of the workers, and vowed to find them jobs at the earliest, but did not identify the provider of the facilities...