A legal standoff between Sanford Health and a medical waste disposal facility over alleged mishandling of human remains has escalated.

Monarch Waste Technologies claimed Sanford delivered a human torso in a plastic container to its Fargo facility in March, according to its lawsuit.

Sanford, in a countersuit filed Thursday, depicts starkly different description of the remains delivered.

"All references to a 'torso' being mishandled or missing are deeply inaccurate, and deliberately misleading," the counterclaim said.

Monarch's Fargo facility has an agreement to process medical waste from Sanford's Healthcare Environmental Services unit. Monarch's lawsuit claims Sanford violated that contract and North Dakota law by allegedly delivering the torso.

Sanford said in a statement the remains were actually a "partial lower body research specimen used for resident education in hip replacement procedures" tagged as such.

Sanford's counterclaim says Monarch "failed to carry out its contracted services."

The Monarch employee who found the remains took a photo and sent proof to the state of North Dakota, according to Monarch CEO David Cardenas. A representative of the North Dakota Department of Environmental Quality said the agency is actively investigating the claims.

"The picture is a torso by definition," Cardenas said. "Unequivocally. It is a torso. I don't know how someone could say it's not by looking at the picture."

Cardenas said he was "shocked" by Sanford's denial of wrongdoing.

The lawsuits were both filed in a North Dakota district court. Sanford's Minneapolis-based attorneys at Maslon wrote in the counterclaim that Sanford and Monarch's contract included the disposal of routine biological material like the remains allegedly delivered.

"Safe and humane disposal in this manner is mandated by North Dakota law," the countersuit said. "[Monarch's] failure to not only perform its contracted duty, but to actually twist its failures into a public allegation of wrongdoing to smear Sanford, starkly demonstrates the bad faith with which [Monarch] has approached this relationship."

Sanford is in the midst of a controversial proposed merger with Minneapolis-based Fairview Health Services.