BANGKOK (Reuters) - A radical plan by the Thai government to put prisoners to work on the country's under-staffed fishing boats has been scrapped, the Foreign Ministry said on Tuesday, following charges the scheme threatened inmates' rights.

Rights groups had also argued the idea would fail to address the fundamental causes of the labour shortage that fuels human trafficking in Thailand's fishing industry.

Thailand is the world's third-largest seafood exporter and its fishing industry employs more than 300,000 people, many of them illegal migrant workers from neighbouring countries who are often subject to ill-treatment.

In December, the country's Labour Ministry said that it would send consenting prisoners who had less than a year left of their sentence to work on fishing boats to ease a labour shortage in the fishing sector and to combat human trafficking fuelled by the shortage.

Thailand is ranked one of the world's worst centres of human trafficking.

The Ministry of Foreign Affairs said in a statement on Tuesday that the plan had been withdrawn, adding that it was an "exploratory idea" and part of a government policy to help prisoners reintegrate into society.