Police in Texas investigating the murder of a teacher and beauty queen in 1960 have arrested the former priest who apparently heard her final confession.

The unsolved killing of Irene Garza, 25, who was last seen at church, has haunted the city of McAllen.

Her bludgeoned body was pulled from an irrigation canal and now, nearly 56 years later, police have arrested the man long suspected of her murder.

Using a walker, a frail-looking John Feit, now 83, appeared in court in Phoenix a day after being arrested at his home in Scottsdale, Arizona, on a murder charge. He is in custody on $750,000 dollars' bail while he waits to be transferred to Texas, but has vowed to fight extradition.

"This whole thing makes no sense to me because the crime in question took place in 1960," he said.

Feit's arrest followed other investigations over the years, including a grand jury probe in 2004 that concluded there was insufficient evidence to charge him.

McAllen police would not comment on what evidence was gathered or presented to the grand jury that finally brought the charge.

"The arrest of John Feit is the first step in providing justice for the murder of Ms Irene Garza. After nearly 56 years, Ms. Garza's family and our community will finally see that justice is served," Hidalgo County district attorney Ricardo Rodriguez said.

Authorities said Ms Garza visited Sacred Heart Catholic Church in McAllen, where Feit was a priest, on April 16 1960. Ms Garza, who was Miss All South Texas Sweetheart 1958, had planned to go to confession that evening. She never returned home.

Her body was found days later and an examination found she had been raped while unconscious, beaten and suffocated.

Feit came under suspicion early on, telling police that he heard Ms Garza's confession - in the church rectory rather than the confessional - but denied killing her.

He later spent time at a treatment centre in New Mexico for troubled priests then became a supervisor and had a part in clearing priests for assignments to parishes.

Among the men Feit helped keep in ministry was child molester James Porter, who assaulted more than 100 victims before he was ultimately defrocked and sent to prison.

Feit left the priesthood in 1972, married and went on to work at the Catholic charity St Vincent de Paul in Phoenix for a number of years, training and recruiting volunteers and helping oversee the charity's network of food pantries, said executive director Steve Zabilski.

He said the charity knew about the suspicion that followed Feit surrounding the killing, but he remained an employee and Feit always denied any involvement.

Mr Zabilski said he was shocked by Feit's arrest "because John is one of the most kind and caring and truly compassionate people that I've ever met. And anyone would say that".

Among the evidence that pointed to Feit as a suspect over the years was his portable photographic slide viewer which was found near Ms Garza's body.

Two fellow priests told authorities Feit confessed to them and one said he saw scratches on Feit soon after Ms Garza's disappearance.

Feit had also been accused of attacking another young woman in a church in a nearby town just weeks before Ms Garza's death. He eventually pleaded no contest and was fined 500 dollars.

Ms Garza's family members and friends had long pushed authorities to reopen the case and it became an issue in the 2014 district attorney's race. Mr Rodriguez had promised that if elected, he would re-examine the case.

Dale Tacheny, a tax adviser in Oklahoma City who had been a priest at a Missouri monastery where Feit had applied to live in 1963, said Feit had confessed to him that he had murdered a young woman, but it was not until years later that he learned that the woman Feit had described was Ms Garza.

He said he eventually told authorities around 2002 and that he had wanted to give evidence before the 2004 grand jury, but was not asked to do so by prosecutors. He said a prosecutor from Hidalgo County visited him to discuss the case last year, but he did not testify before the most recent grand jury.

Mr Tacheny said he had travelled in recent years to the McAllen area to support Ms Garza's family members' efforts to get the case reopened.