By Jonathan Davies

A clothing factory in Cambodia which supplies several well known retailers has been accused of human rights abuses.

Human Rights Watch (HRW) claims it has uncovered evidence of discrimination and anti-union practices at a factory which supplies retailers like Marks & Spencer, H&M, Armani, Adidas and Gap.

It claims to have amassed evidence of conditions on 73 factories through interviews with 340 people.

The human rights group said that short-term contracts prevent workers from exercising their rights. It also claims to have found evidence of staff being forced to work overtime and pregnant women being discriminated against.

In its investigation, HRW said that factories that supply major retailers often sub-contract their work to much smaller factories where employees are hired on a casual basis, and where conditions are much worse.

"These international apparel brands need to help labour law compliance by publicly disclosing and regularly updating the names and addresses of their factories," says HRW researcher Aruna Kashyap.

Marks & Spencer refused to disclose the names of its suppliers, but has committed to doing so in 2016. HRW believes that 13 of the 73 factories supplied products to the UK retailer.

"We have not been presented with any evidence to support these claims," a Marks & Spencer spokesman said. "If HRW comes to us with any evidence we will, of course, investigate."

"All our supplier factories are audited regularly by third party, independent auditors and are visited by M&S compliance managers," the company said.

Adidas, Gap, and H&M individually told Human Rights Watch that they are taking steps to address the problems put forward.

H&M told the BBC that any suppliers found to be sub-contracting their work to smaller factories would lose their contracts.

"H&M has distributed a translated copy of its suppliers' list to local unions and labour rights groups to encourage whistle-blowing on undeclared units," the company said.

Gap said: "We are investigating the alleged labour practices highlighted in this report. If true, they are unacceptable and violate our code of vendor conduct."

Adidas said: "The vast majority of our supply chain in Cambodia is unionised.

"Workers have the right to join unions of their own choosing."