A Queensland funeral home accused of swapping a grandmother’s expensive coffin for a cheap pine box has said it was only done so the pricey casket wouldn’t crack.

On Thursday police confirmed they were investigating an alleged fraud after a Rockhampton family accused a funeral home of switching a 74-year-old woman’s $1,700 silky oak coffin for a cheap pine box just before her cremation. The family of Janice Cecilia Valigura said letters written by her grandchildren and placed on her heart were thrown away.

On Friday funeral director Tony Hart told the Courier-Mail his company, Harts Family Funerals, only moved the body to a crematorium in a cheaper box to protect the structural integrity of the casket her family paid for.

“The coffin she was cremated in was the same one that the family bought,” Hart said.

Hart said there had been a delay at the crematorium which meant the coffin had to be placed in a freezer before cremation and the cheap pine box was a transfer shell.

Queensland police are still investigating the matter and have spoken to people from the funeral parlour and the crematorium.

Valigura’s son Mick Valigura has said the family was shocked by what had happened.

“I just don’t want this to happen to anyone else,” he told the Morning Bulletin.

On Thursday the president of the Queensland Funeral Directors Association, Anton Brown, had said changing coffins was not common practice in the funeral industry.