Some of the world's biggest tech companies have been hit with a landmark lawsuit from 14 of the world's poorest families.
Apple, Google, Microsoft, Dell, Tesla are accused of exploiting child labour, in the mines of the Democratic Republic of Congo (DRC).
The families want compensation for death and injuries to children mining cobalt - a key component of tech gadget batteries.
It's the first time that tech companies have faced such a legal challenge.
Cobalt is used in the rechargeable lithium batteries used in millions of products sold by the companies every year.
According to the Guardian, demand for cobalt has tripled in the past five years and is expected to double again by the end of 2020.
More than 60 percent of cobalt comes from the DRC.
The families say their children were working at mines owned by UK company Glencore, which sells cobalt on to Umicore, a company based in Brussels. That company then onsells the product to Apple, Google, Tesla, Microsoft and Dell to be used in batteries, the Guardian reports.
In court documents, the families describe how their children were driven by extreme poverty to work in sites mining cobalt, where they were paid as little as US$2 (NZ$3) a day, reports the Guardian.
Lawyers representing the families allege that the companies had "specific knowledge" that the cobalt they used in their products was linked to child labour.
The tech companies all have the resources to regulate how they get the cobalt they need, the court documents said.
A spokesperson for Glencore told the Guardian it "supports and respects human rights in a manner consistent with the universal declaration of human rights."
In a statement, Apple said it was "deeply committed to the responsible sourcing of materials that go into our products".
"We've led the industry by establishing the strictest standards for our suppliers and are constantly working to raise the bar for ourselves and the industry."
Dell said it was "committed to the responsible sourcing of minerals, which includes upholding the human rights of workers at any tier of our supply chain and treating them with dignity and respect".
It said it had "never knowingly sourced operations using any form of involuntary labour, fraudulent recruiting practices or child labour" and was "currently investigating the allegations."
Microsoft, Google and Tesla were also approached for comment by the Guardian.