British online fashion group Boohoo is under fire for allegedly exploiting Pakistani workers. The brand said on Wednesday that it is investigating a Guardian report that its suppliers were underpaying workers in Pakistan.

 The Guardian reported that employees at two factories in Faisalabad making clothes for Boohoo were earning Rs10,000, or £47 ($62) per month that is below the legal monthly minimum wage for unskilled labour of Rs17,500.

The report added that it had video and photographic evidence to support the claims of potential safety issues such as parking of the motorbikes in the indoor areas next to flammable materials. In the rush to produce clothes for the western market, insiders claimed workers would sometimes do 24-hour shifts.

Responding to the allegations, Boohoo said it had called upon inspection and compliance specialists Bureau Veritas to probe the claims on the ground in Faisalabad.

“As we have previously stated, we will not tolerate any instance of mistreatment or underpayment of garment workers,” Boohoo added in a statement.

Earlier this year, Boohoo has been accused that one of its suppliers in England paid workers much less than the national minimum wage.

“Any supplier who does not treat their workers with the respect they deserve has no place in the Boohoo supply chain,” its statement added.

Another factory whose working conditions are criticised in the report, Madina Gloves, strongly refuted the allegations.

“The situation on the ground is completely different. The reporter never visited my factory and I challenge him to bring forward a single quote from the workers of the factory. I am considering taking him to the court,” the owner Muhammad Saleem Shahzad told AFP.

Shahzad added that since the article had published, he had already received calls from three different UK clients to cancel orders.

“I want to ask what service this report has done to my employees who are going to lose their job now?”

The Guardian report comes after Boohoo in November appointed Brian Leveson to help “deliver long-lasting and meaningful change” to the group’s supply chain and its business practices.

Leveson is best known for heading a 2012 inquiry into UK media standards following the hacking of celebrities’ phones by the now-closed News of the World tabloid, which was owned by Rupert Murdoch.