The Daily Mail reports that detectives will put pressure on Fr Jose Pacheco to break his Catholic vow of silence.
They have already spoken to him "informally" about the bond he developed with Madeleine’s parents in the days after she vanished.
Now they plan to question him in a bid to force him to reveal if Kate confessed to him she had killed her four-year-old daughter.
An assistant to the priest said he had a duty to God not to speak out.
Fr Pacheco met the McCanns the day after Madeleine vanished from their holiday apartment on 3 May. As the search for Madeleine continued the couple attended daily Masses at his church.
But when the finger of suspicion was pointed at the McCanns their relationship with the priest changed, according to locals. They did not say goodbye and handed the church keys to an Anglican priest.
Maddie's mum's confession (Daily Mail, 15/9/07)
LINKS (not necessarily endorsed by Church Resources)
Madeleine McCann (Wikipedia)
Bring Madeleine Home
Missing Madeleine's desk ready (CathNews, 31/8/07)
Pope prays for Madeleine (CathNews, 31/5/07)
Madeleine's parents seek miracle (CathNews, 24/5/07)