A search warrant shows police are investigating whether a Virginia man gave his children poisoned doughnuts to take to his estranged wife.

The Washington Post reported Thursday that tests on the doughnuts showed the chemical naphthalene, which can be fatal. It's commonly found in mothballs.

Investigators wrote that the father sent the box along to his wife's home last November.

According to the search warrant, a judge had granted the wife a protective order against her husband because he had allegedly threatened to kill her before.

The search warrant says an adult daughter and the mother noticed a charcoal-like substance inside a doughnut. A lab determined it was naphthalene.

The man has not been charged with a crime, and The Post did not name him. The case remains under investigation.

___

Information from: The Washington Post, http://www.washingtonpost.com