"Rwanda has continued to illegally profit from DRC's mineral wealth," Amnesty Secretary General Agnès Callamard said.
The militia controls access to numerous mining sites in eastern Congo and illegally transports minerals across the border into neighbouring Rwanda, the report said.
Amnesty said the rebels are forcing tens of thousands of people to work at mines around the town of Rubaya in North Kivu province and around Lomera in South Kivu.
The human rights organisation documented killings, torture, arbitrary detention and forced labour, saying some of the abuses could amount to war crimes.
Amnesty said it interviewed 26 people, including miners, mining experts, mine owners and relatives of victims, and also analysed photographs and video footage.
Neither M23 representatives nor the Rwandan government responded to Amnesty's requests for comment on the allegations.
The report documents the deaths of 18 miners. According to witnesses and relatives, 10 were beaten to death and two were shot dead.
Miners and civilians living in the area also described being tortured or otherwise abused by M23 fighters or security forces, Amnesty said.
"International actors must end their silence about M23's atrocities and the smuggling of minerals from conflict affected areas. They need to hold perpetrators, including Rwandan government officials, accountable," Callamard said.
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