He told BBC Radio 4's Today programme that it depends on a number of factors including:
- How the body has been buried
- What condition it was in when it entered the ground
- How expensive the coffin was
- Whether modern embalming techniques were used
He said: "I think it is certainly possible that they could find residual traces of radioactive material," but added it was doubtful they would find solid evidence of poisoning if only bones remain.
More top news
A toddler survived for days on his own after his mother collapsed and died as she fed his one-year-old brother - who also choked to death.
A police officer has won a legion of fans after a picture of him comforting a baby girl caught up in a horror car crash went viral.
A mother has claimed that she was left a spiteful note from fellow diners accusing her son of "ruining" their meal with his screaming.