"He put his arms up in the air and he seemed to shudder, like he was vibrating," Said Mrs Kiddie said. "He was shouting in tongues.
"He picked up the photo of dad from the coffin and studied it for a while. Then he went down on his knees and shouted 'Wake up Harold!' and thumped on the casket.
"I was horrified, absolutely horrified."
For a moment Mrs Kiddie and other family members, who were stunned, thought the mystery man would try to open the casket.
"Everybody was turning around and looking at each other. We were all sort of puzzled wondering 'Do you know this person?'."
He then turned to the mourners and bowed slightly, then went and sat down with a well-dressed companion.
Mrs Kiddie's husband, Ross, confronted the man after family members had carried Mr Ritchie's casket to the hearse.
The man told Mr Kiddie that he was a member of the Fellowship Church and he felt the need to "spread God's words".
John Rhind funeral director Lance Grey said he thought what was happening was part of the ceremony until the man began telling Mr Ritchie to wake up.
"We had no idea who it was, it happened at a time when tributes were being paid to the deceased, and this was the last tribute, or so we thought.
"We thought it was very unusual."
Mr Grey said it was the first time he had heard of something like this happening in Christchurch.
Other funeral homes would be alerted, he said.
Mrs Kiddie said her father had a terrific sense of humour, but she did not think he would have found what happened at his funeral funny.
"I don't think he'd be very pleased. He would've said, 'God, get this crackpot out of here!"'
Mrs Kiddie said the imposter needed to be stopped before he caused more grief to families.