The archbishop-emeritus of the Roman Catholic Church in the Philippines has initiated an investigation into the arrest of a priest while he was bringing a 13-year-old girl to a motel in Marikina City on July 28. The priest, Arnel Lagarejos, has been accused of sexually abusing the girl more than once.

Lagarejos, the parish priest of St John the Baptist in Taytay city in the Philippines' Rizal province, was arrested following complaints from the victim and her mother. He was relieved of his duties immediately after his arrest.

The victim said the man had booked her through a pimp and molested her on two previous occasions. The day he was arrested was the third booking.

She also alleged that the priest had threatened her by pointing a gun at her against going out with any other man. She also said that she did not know the man abusing her was a priest.

Police said they too were unaware that the arrested paedophile was a priest until his colleagues from Taytay identified him and revealed his vocation to them.

Lagarejos was subsequently charged with human trafficking and could also face criminal charges.

Archbishop Emeritus Oscar Cruz, who is leading the probe, told reporters that Francisco de Leon, the Bishop of Antipolo, had assigned him the task of looking into the "paedophile case".

"This case is considered the gravest violation of the commandments, abuse of minors... I don't know [how long the investigation would take], it depends on how fast I could gather evidence ... how fast I could get my testimonies," he said, according to Inquirer.

He also said that the Vatican will first decide on the priest's case and forward the ruling to De Leon.

Meanwhile, Marikina Mayor Marcelino Teodoro told The Manila Times in a phone interview on Monday (31 July) that the truth will not be concealed in the investigation. "There will be no whitewash in the case. No pressure [from the Catholic church]."

The case has emerged as the Vatican is struggling to cope with rising sexual offence cases against its priests. Cardinal George Pell, a high-ranking Vatican cleric, recently appeared in an Australian court to face historical sexual abuse charges.

Soon after Pell's indictment, Vatican police had discovered a drug-fuelled gay sex party underway at a cardinal's apartment in the city.