Engel died of natural causes and was buried in a private ceremony in the northern German city of Hamburg last week.
He was known for his part in the wartime massacre of 59 Italian prisoners in Genoa in northern Italy on May 19, 1944.
The execution was in revenge for an attack on a cinema in which five German soldiers were killed.
In 2002, a Hamburg court sentenced Engel to seven years jail for murder after finding he ordered the prisoners’ execution.
Engel maintained he had observed the killings but did not supervise the executions.
Germany's Federal Court of Justice threw out the conviction in 2004.
In their ruling, the judges said that although they upheld the court finding that Engel ordered the execution, the charge of murder had not been sufficiently proven and would have required a retrial which could not take place because of his advanced age.