A second man has filed a complaint accusing a group of Catholic priests in Spain of sexual abuse in a case Pope Francis has said has caused him "great pain", a judicial source said Wednesday.
Police on Monday arrested three Catholic priests and a religion teacher in the southern city of Granada after a 24-year-old man accused them of molesting him and other children.
Pope Francis said Tuesday he had personally ordered an investigation into a case after the unidentified man sent a letter to the pope telling him of how he had been molested when he was an altar boy.
"I read it. I called the person and I told him, `Go to the bishop tomorrow,` and then I wrote to the bishop and told him to start an investigation," Francis said in response to a question by a Spanish reporter on his plane from Strasbourg, France, where he had addressed the European Parliament.
"How have I received this news? With great pain, very great pain, but the truth is the truth and we should not hide it."
A second man presented a formal complaint against the priests and religion teacher at a duty court in Granada on Monday, a judicial source told AFP.
Spanish media reported that he is a former altar boy and friend of the man who sent the letter to the pope.
Judge Antonio Moreno, who is leading the investigation into the case, began questioning the suspects on Wednesday at a criminal court in Granada, the judicial source said.
"They have started being heard, the first one was taken to court early this morning," the source said.
The man who sent the letter to the pope said he was "repeatedly" abused while serving as an altar boy between the ages of seven and 18.
"The most frequent sexual practices ranged from massage to masturbation and kisses on the mouth," he wrote in a letter, which was reprinted in Spanish media.
The Archbishop of Granada Francisco Javier Martinez and six priests prostrated themselves on the floor in the city`s cathedral in front of the altar during a mass in a gesture of apology to victims of abuse.
After a series of paedophilia scandals in the Church over recent years, Pope Francis has taken a zero-tolerance approach since taking over last year from Benedict XVI.