Adrian Gibson, a lawyer who also owns a car rental car agency on Long Island, Bahamas, said the man now charged in the homicide failed to return a rental car the week before the slaying.
When he tried to report the vehicle stolen, Gibson said police didn't take his concerns seriously even though the man who rented the car had a criminal past.
"The officers in Long Island fell down on the job," Gibson told CBC News by telephone.
"I feel that if they'd paid attention to the earlier complaints, relative to the vehicle, or relative to the background — whatever the case may be — maybe certain things wouldn't have happened."
Harding, a British citizen with a long and distinguished medical career in B.C., was found dead at his winter home in Clarence Town on April 2.
Accused served time for manslaughter
Bahamian authorities have charged a local man, 43-year-old Moses Morris, with murder in Harding's death.
Stephen Dean, assistant police commissioner, confirmed reports Morris recently completed a lengthy sentence for manslaughter.
Morris made a court appearance this week and is scheduled to return to Supreme Court in the Bahamas on June 19. He has also been charged with one count of credit by fraud and one count of damage related to the car he rented from Gibson's agency, according to the Nassau Guardian.
Gibson said Morris rented a Honda Fit from his agency on March 23. The vehicle was found in a ditch, concealed with branches, five days later.
He wants to known what — if anything — was known about the suspect's movements and his potential involvement in a series of break-ins on the island in the days before Harding was killed.
Gibson said he's confused by police actions because an officer came to his agency on the day Morris was set to return the vehicle asking questions about the ex-convict.
After the vehicle was found, though, Gibson said police showed little interest in taking a formal complaint. He said a senior officer told him he didn't work weekends.
Appalled by attitude
He has since written a blog posting calling for better policing.
"I am appalled by the nonchalant, don't care attitude taken by police in this entire episode," he wrote.
"There are many Long Islanders who have also complained relative to their handling of information and the so-called manhunt."
Gibson said he is writing a letter of complaint to the commissioner of police and the minister of national security calling for better training for police on Long Island.
He also said he hopes Canadians won't be scared away.
"This is an unfortunate incident," he said. "I want to encourage Canadians and others to know that Long Islanders are great people."
The assistant commissioner would not comment on Gibson's complaints.