Robert Murat has said he is "frustrated" at the prospect of being questioned for a second time in connection with missing Madeleine McCann.
The British ex-pat was the first person Portuguese police identified as a "suspect" at the time of her disappearance seven years ago.
Mr Murat, who has always denied any involvement, later successfully sued 11 newspapers winning libel damages of £600,000.
He has previously claimed the ordeal almost destroyed his life and said he felt like a "fox being pursued by hounds".
Exactly when he will be re-interviewed as part of a fresh investigation by British police he does not know.