Father-of-two Bassam Safwat Atta, 35, was found lying face down drenched in blood with a single gash in his neck at his flat in Dairut, Asyut governate, on Friday, according to neighbour, Mokhles Nageh.
Mr Nageh, who is also a Copt, told World Watch Monitor: "This crime was meticulously planned and carried out by a professional killer."
Dr Atta's wife, who was said to be working at a hospital in a nearby city, asked their neighbour and a relative to break into the property after repeated failed attempts to phone him and learning he had not arrived at work that day.
Dr. Michael Ramsey, a colleague of Dr Atta's a Dairut hopsital, told World Watch Monitor: "It was a big shock - Bassam was a very close friend.
"He was called 'the doctor of the poor' because he treated many poor people in his private clinic for free. Everyone - Muslims and Christians, alike - loved him."
Dr Atta's body underwent a hospital post-mortem examination on Friday evening, before his funeral was held in El-Kodeya the next day.
His death comes ten days after Youssef Lamei was murdered in Alexandria after being threatening by Salafist Muslims and one week after the bodies of Copts, Gamal Sami, 60 and his wife, Nadia, 48, were found.
Police have been keen not to refer to the deaths of Gamal Sami and Nadia as sectarian, claiming they died during a robbery.