Three suspected Muslim separatist rebels have been charged in connection with the kidnapping of Irish priest Fr Michael Sinnott in the Philippines, who was released unharmed after 31 days in captivity last week.

Director-general of the national police Jesus Verzosa said police filed charges of kidnapping for ransom and illegal detention with the prosecutor's office of southern Pagadian city on Friday.

Fr Sinnott was snatched from his compound on 11 October by six gunmen who broke into the Columban House in Pagadian City in Zamboanga del Sur province, 890km south of Manila.

The three suspects, alleged members of the Moro Islamic Liberation Front (MILF), have denied involvement and said that they helped pressure the kidnappers to release the 79-year-old priest.

Prosecutors will review the evidence to determine whet­her there is enough to file the case in court. Verzosa said the three men were among six gunmen who seized Fr Sinnott from his residence.

The region is home to several armed groups fighting for Muslim self-rule in the predominantly Catholic country.

Mohagher Iqbal, head of the rebel group's negotiating panel for peace talks with the government, has denied guerrillas were involved in the abduction and said the group even exerted "moral pressure" on the kidnappers to release the elderly missionary.

On Thursday, rebel representatives handed him over to government authorities.

Fr Sinnott said his kidnappers demanded a $2m (€1.34m) ransom but he did not know whether any money changed hands.

The Irish and Philippine governments said no ransom was paid.