Even after the passing away of John Demjanjuk, suspected of being Ivan the Terrible during World War II, controversy continues to surround both his life and death. Demjanjuk's attorney, Ulrich Busch, filed a complaint on Wednesday with Bavarian prosecutors claiming that pain medication administered to his client helped lead to his death as he awaited an appeal of his conviction on Nazi war crimes. In a 12-page complaint obtained by The Associated Press, Busch asks prosecutors in Rosenheim, Germany, to open an investigation into five doctors and a nurse on suspicion of manslaughter and causing bodily harm. Anyone in Germany has the right to file such a complaint, and Rosenheim prosecutor Juergen Branz said his office was obliged to investigate all such claims to decide whether to open a case. Branz refused to comment further, and the main doctor cited in the complaint, whose name cannot be released due to German privacy laws, also declined to comment. Ukrainian-born Demjanjuk, who lived for decades in Seven Hills in suburban Cleveland and worked as a mechanic in the auto industry, was convicted by a Munich court in May 2011 on 28,060 counts of being an accessory to murder while working as a guard at the Nazis' Sobibor death camp in occupied Poland. Demjanjuk denied ever having been a guard, saying he had been mistaken for someone else. He was sentenced to five years in prison, but was released pending an appeal, and died a free man in a nursing home in the southern Bavarian town of Bad Feilnbach on March 17 at age 91. Demjanjuk suffered from terminal bone marrow disease, anemia, chronic kidney disease and other ailments. Doctors were unable to determine an exact cause of death from his autopsy but said "there was no indication" of unnatural causes. In his complaint, Busch says there is evidence that Demjanjuk had been given the pain medication Novalgin regularly, including the night before his death. He also cites the manufacturer's warnings that such medication should be avoided by patients suffering from blood or kidney problems. "The prolonged use of Novalgin, given the known conditions of my client, was absolutely incorrect and capable of causing the death of the defendant," Busch said in his complaint. He also said the night before he died, Demjanjuk complained of pain in the stomach area and was given Novalgin by the nurse on duty. "Had the nurse ... fulfilled his duty and called the emergency doctor immediately, the deceased would have been taken to a hospital and would still be alive today," Busch said. Demjanjuk is probably best known as someone he was not: the notoriously brutal guard Ivan the Terrible at the Treblinka extermination camp. That was the first accusation against him, which led to his extradition from the U.S. to Israel in the 1980s. He was tried, convicted, and sentenced to death, only to have the Israeli Supreme Court unanimously overturn the verdict and return him to the U.S. after it received evidence that another Ukrainian, not Demjanjuk, had been that Nazi guard. He has become at least one of the faces of the Holocaust, Israeli historian Yehuda Bauer said in a telephone interview from Jerusalem at the time of Demjanjuk's release in Israel. His case illustrates the principle that whenever even a very low-ranking Nazi criminal can be found and convicted, the importance is not in the sentence, not in the amount of time such a person may have to sit in jail ... the important thing is to bring the crime to the attention of the general public. But attorney Yoram Sheftel, who defended Demjanjuk in the Israeli trial, criticized the German conviction of Demjanjuk as a Sobibor Wachmann, the lowest rank of the prisoners who agreed to serve the Nazis and were subordinate to German SS men, while higher-ranking Germans had been acquitted. I can only call it a prostitution of the Holocaust, Sheftel told Army Radio at the time. [Demjanjuk] was found innocent. To convict him was a ludicrous and criminal act. The German court ruled that he was not at Treblinka; the trial was just a show. After his release in Israel, Demjanjuk returned to his suburban Cleveland home in 1993, and his U.S. citizenship, which had been revoked in 1981, was reinstated in 1998. He remained under investigation in the U.S., where a judge revoked his citizenship again in 2002 based on Justice Department evidence suggesting he concealed his service at Sobibor. Appeals failed, and the nations chief immigration judge ruled in 2005 that Demjanjuk could be deported to Germany, Poland or Ukraine. After his death, Demjanjuk's son, John Jr., said in a telephone interview from Ohio that his father apparently died of natural causes. Demjanjuk had terminal bone marrow disease, chronic kidney disease and other ailments, although local authorities said the cause of death was still being determined.