Philippine immigration authorities have arrested an American Roman Catholic priest accused of sexually assaulting altar boys in a remote central town, in a case one official described as "shocking and appalling".

Key points: Reverend Kenneth Bernard Hendricks has lived in the Philippines for 37 years

Reverend Kenneth Bernard Hendricks has lived in the Philippines for 37 years A US court issued a warrant after complaints from Filipino minors

A US court issued a warrant after complaints from Filipino minors Each of the 50 counts of molestation is punishable for up to 30 years in prison

Reverend Kenneth Bernard Hendricks, who has been indicted in Ohio for alleged illicit sexual conduct in the Philippines, was arrested in a church in Naval town on the island province of Biliran on Wednesday, Bureau of Immigration spokeswoman Dana Sandoval said.

Each of the 50 counts is punishable with up to 30 years in prison, US attorney Benjamin Glassman said at a news conference in Cincinnati.

Federal court records do not show an attorney for Mr Hendricks who could comment on the charges.

An Ohio court had issued a warrant for the arrest of 77-year-old Mr Hendricks, who has been living in the Philippines for 37 years, Ms Sandoval said, adding the US criminal case stemmed from complaints from Filipino minors who were allegedly victimised in the Philippines.

There was no immediate reaction from the US embassy, Philippine Catholic Church officials or Mr Hendricks, who was flown to Manila and detained in an immigration cell.

'People like him must be kicked out'

The suspect allegedly abused victims who served mostly as altar boys in Naval, in 50 counts of molestation in his residence, Ms Sandoval said.

Mr Glassman said they believed Mr Hendricks lived with multiple boys and molested victims both alone and with others.

Victims told investigators that Mr Hendricks would kiss them, touch their genitals and initiate oral and anal sex.

One reported more than 40 sexual encounters with the local priest.

"The victims were in his house and the abuses were committed while he was taking a bath with each of them," Ms Sandoval said.

Mr Kendrick's alleged victims were reportedly warned they would be locked up in jail if they told anyone about the abuses. ( Bureau of Immigration PIO via AP )

US authorities provided information about the alleged sexual assaults to the Philippine Government, she said.

The victims were reportedly warned they would be locked up in jail if they told anyone about the abuses, she said.

Mr Glassman said 10 victims had come forward with their statements.

Of the five interviewed, the youngest was seven years old at the start of the abuse.

The US embassy may revoke Mr Hendrick's passport to help Philippine authorities immediately deport him, the Immigration Bureau said in a statement.

Mr Hendricks is "a fugitive from justice that poses a risk to public safety and security", Ms Sandoval said.

"We will not allow sexual predators to prey on our children.

"People like him must be kicked out and banned from the Philippines."

Mr Glassman said he wanted to prosecute the case in Ohio, but his office was still coordinating with Philippine officials to determine which jurisdiction would proceed first.

He added there was reason to believe others had been abused by Mr Hendricks, whose travel records showed he returned to the US for several months each year.

Mr Glassman said Mr Hendricks had a residence in the Cincinnati area, but could not comment on whether he served as a local priest there.

The Archdiocese of Cincinnati listed Mr Kendricks as a "missionary in Asia" on its website, but later issued a statement saying he "is not, nor has ever been, a priest of the Archdiocese of Cincinnati".

Steve Francis, special agent in charge of Homeland Security Investigations in Michigan and Ohio, pleaded with other victims to come forward.

He said the allegations against a man he described as "in one of the highest positions of public trust" were very disturbing.

Duterte weighs in

Rodrigo Duterte called the Catholic Church "the most hypocritical institution in the entire Philippines". ( AP: Wong Maye-e )

Philippine President Rodrigo Duterte has repeatedly lashed out at the dominant Catholic Church and its priests over such abuses, saying he himself, along with other students, were sexually molested by an American priest in their high school days.

In separate speeches on Wednesday (local time), the volatile leader claimed almost 90 per cent of Catholic priests were homosexual and also admonished Catholics.

"Kill your bishops, they are useless fools. All they do is criticise," he said.

"I'm telling you, the most hypocritical institution in the entire Philippines is the Catholic church and the Pope knows that."

A Catholic priest and Duterte critic, Amado Picardal, said the President's remarks on the church may be aimed at diverting public attention from his widely criticised deadly war on drugs, the Government's failure to stop the smuggling of illegal drugs into the country, continuing poverty, corruption and other issues.

He said Mr Duterte may also feel threatened by the Catholic Church, which played a role in the ouster of two Philippine presidents, including the 1986 overthrow of dictator Ferdinand Marcos.

"Many people believe that his controversial statements are simply a way of diverting the people's attention from the real issues raised against him," Mr Picardal said.

AP