The family of Dale Porch, 46, said the man collapsed on his front porch after being dropped off from work at the Regional Transportation District early Nov. 2 and the mail carrier allegedly delivered mail to the home before the body was discovered by porch's adult son, KMGH-TV, Denver, reported Friday.
"When we found the body later around noon, he was still warm. Maybe if the mailman had done something, he would still be here," said Kimberly Cordova, Porch's sister-in law.
A U.S. Postal Service spokesman said the agency is investigating the allegation and the carrier has been temporarily removed from the route.
Officials said the man told bosses he thought the body was a leftover Halloween decoration.
"This is a very unfortunate situation and one that probably would not happen any other time of year. We are very sorry for the family's loss and have conveyed our condolences, and those of the carrier, to the family," the spokesman said.
The family is awaiting the results of an autopsy to determine the cause of Porch's death.