(CNN) A Columbus, Ohio, doctor is suing the hospital system that accused him of overprescribing pain medication to more than two patients near death .

Dr. William Husel was fired in December 2018 during an internal investigation by his former employer, Mount Carmel Health System. In June, Husel was indicted on 25 counts of murder . He has pleaded not guilty.

The lawsuit, filed the day after Christmas, says that Husel "has suffered perhaps the most egregious case of defamation in Ohio's recent history." It claims that Mount Carmel, former CEO Ed Lamb and Trinity Health Corporation, the parent company of Mount Carmel, knowingly made false and defamatory statements to the media multiple times.

Husel is asking for "far greater than" $50,000 in presumed and actual damages, along with punitive damages and attorney's fees for defamation and breach of contract.

Husel followed hospital policy, suit claims

The June indictment documents allege that the deaths took place from February 2015 to November 2018. Each of the 25 counts could carry a penalty of 15 years to life if there is a conviction, according to a news release from the Franklin County prosecutor's office.

During prosecutors' initial conversations with Mount Carmel, it was revealed that a doctor, who was later identified as Husel, was "administering doses of fentanyl at a level that they internally believed were inappropriate and not for a legitimate medical purpose," Franklin County Prosecutor Ron O'Brien said at a news conference in June announcing Husel's indictment.

The investigation also found that the doses, which ranged from 500 and 2,000 micrograms, "were designed to hasten the death of the patients that were being treated," O'Brien said.

Husel's lawsuit says the deaths all were caused by "natural causes after the removal of full life support." The lawsuit also says Husel followed hospital policy for administering medication.

"The hospital knew full well that no policies were violated because the actual policies in effect explicitly permitted and encouraged the care Dr. Husel and the nurses provided to patients undergoing palliative withdrawal," the lawsuit said.

"These false accusations destroyed Dr. Husel's life" because of the "non-stop media barrage" that led prosecutors to charge Husel with 25 counts of murder and the state attorney general to call Husel a "serial killer," the suit said.

The lawsuit also claims Mount Carmel and Trinity refused to provide Husel with a defense lawyer that he says they agreed to provide under his employment contract.

In a statement to CNN, Mount Carmel Health System said the allegations by Husel are "unfounded."

"We completed an extensive review of patient care provided by Dr. William Husel and stand by our decisions," the statement said. "Mount Carmel's focus continues to be on caring for our patients."

CNN has reached out to Husel's attorney but has not heard back.

Nurses and a pharmacist are also suing the hospital

Nine nurses and a pharmacist who worked with Husel are also suing Mount Carmel for defamation and wrongful termination

The plaintiffs claim in their 145-page lawsuit that Mount Carmel, Lamb and Trinity Health Corporation fired those who worked with Husel for their alleged complicit behavior in following through on Husel's prescriptions.

They allege that the hospital system then changed policies concerning medication dosage that risked patient care for the purpose of protecting its image. Through these acts and the hospital's media relations campaign managing the scandal, the hospital defamed their reputation and made it difficult to find new jobs, the former employees said in the lawsuit, which also was filed this month.

Plaintiffs are asking for a minimum of $25,000 per plaintiff, but ideally want their "respective salaries at the time of termination," according to the lawsuit. They also are asking for the cost of tuition of nursing school or advanced clinical degrees, as well as punitive damages and attorney's fees.