A longtime priest at one of the country’s largest and most prominent conservative Anglican churches has been fired for repeatedly using a church computer to surf for pornography, an official at the Fairfax City church said.

The Rev. Marshall Brown was associate rector at Truro Church, whose clergy members helped lead 14 Virginia parishes to break away from the Episcopal Church after the 2003 election of the denomination’s first openly gay bishop.

With more than 1,200 members, Truro was one of the biggest parishes in the Episcopal Church, the American province of Anglicanism.

Truro’s rejection of what its congregants saw as a non-biblical, liberal tilt in the denomination made international news. Dozens of Episcopal churches have since joined an umbrella group of religious conservatives who oppose the acceptance of same-sex relationships and the idea that non-Christian religions have equal access to God.

In 2005, Truro arranged for Brown, now 57, to receive treatment for an Internet addiction after he reported having a problem, according to Bishop Martyn Minns, who was Truro’s rector at the time and is now bishop of the Convocation of Anglicans in North America, the umbrella group of breakaway churches.

Minns, one of the leaders of Anglican conservatism, said in an interview this week that in 2005, he didn’t ask his then-assistant for details about what kind of sites he was using — sexual or otherwise. The addiction experts who treated Brown told Minns that “there was nothing illegal or involving children,” but beyond that, Minns said, “I didn’t ask too many questions.”

Then, last month, Brown was removed for accessing “Web sites that would be considered pornography,” Truro Executive Director Warren Thrasher said.

Minns, who has known Brown since the two were in seminary together in the 1970s, said he is now launching an investigation into what happened and whether Brown should be stripped of his priestly credentials.

“Part of my thing now is to dig deeper,” Minns said. “I was assured [in 2005] that he had a program for whatever he needed not to be addicted, and it was no longer a problem. I don’t know now, based on what’s happened, how much I can trust those assurances.”

On Dec. 19, between two Sunday services, church leaders held a meeting to talk to members about Brown’s firing.

Parishioners were told to direct any questions from outsiders to the church leadership. A few, who did not want their names used for fear of being ostracized, said they were concerned that the addiction of one of their top clergy members had been kept quiet for years and that specific details had still not been given. Others said they felt that the matter was dealt with properly.

“That’s why you have a vestry. You pick them and invest in them and expect them to do what’s right,” said Ernie Wakeham, 70, a member from Oakton. “I think it’s appropriate to not say details. That’s something in my viewpoint that’s between him and God.”

Minns said Brown “is in shock” and is getting treatment again.

Reached at home this week, Brown said he deeply regrets the way his tenure at Truro ended and the way his actions have affected his family and church.

He declined to go into the specifics of what happened, but said, “The church, Bishop Minns, they’ve treated me fairly. If I were a denominational leader, I would do exactly the same thing.”

Brown had been at Truro for about 10 years. As one of three associate rectors, his position focused on pastoral care for people dealing with illnesses or other struggles, Thrasher said. He also worked to support Truro’s Bible study groups at parishioners’ homes. “There are some who feel churches are sometimes overly vindictive. Every one of us makes mistakes,” Thrasher said. “We’re in the process of trying to figure out how to make this a restorative process for him.”

Thrasher said that the discovery of Brown’s use of pornography prompted the church to look at all its computers and that another employee was found using sites “with suggestive names.” Truro called the Fairfax City police, who took that computer. Police Sgt. Dan Grimm said that there was an ongoing investigation but that it wasn’t clear whether any crime had been committed.

Truro is one of nine Virginia congregations enmeshed in a complex and costly legal fight with the Episcopal Church and the Episcopal Diocese of Virginia over church properties, which are worth tens of millions of dollars. The most valuable are Truro and the Falls Church, both large, historic properties.

The legal conflict has split into two cases and has involved multiple appeals over who controls property when a church splits, what role the state should play in determining how churches are governed and other questions. The next phase of the legal battle is scheduled for April.