
Thaksin has been living abroad since the military overthrew his government in a bloodless coup last September.
"Thaksin has informed us that he is living overseas and he is not able to come to see police," an unnamed spokeswoman for the Justice Ministry's Department of Special Investigation was quoted by AFP as saying.
Pojaman was also unable to show up due to medical treatment abroad. She had been hospitalised in Singapore last month, but officials could not say if she was still there.
The couple has been accused of fraudulent filings to the Securities and Exchange Commission over the 2003 listing of a property company owned by his family.