The discovery was made in an area that the M23 rebel movement, which is supported by neighboring Rwanda, recently left after the Congolese army launched an offensive.
The information was provided by South Kivu governor Jaques Purusi and by an independent organization.
"Currently, we have identified two sites: a mass grave with 30 bodies in Kiromoni, near the border with Burundi on the Congolese side, and another one in Kavimvira where 141 bodies were found," Purusi told the AP news agency.
The information has not been independently confirmed. The AP has sought comment from the M23 rebel movement but has been unsuccessful.
