Haggard founded New Life in his basement in 1984 and oversaw its growth to an influential megachurch with roughly 15,000 members.
Haggard is the former president of the National Association of Evangelicals, a group that says it represents millions of people in 45,000 church congregations nationwide. He and other evangelical leaders participated in weekly conference calls with senior White House aides during the Bush administration.
In November 2006, allegations surfaced that Haggard had a three-year relationship with Mike Jones, a male escort, involving drugs and sex for money. After those allegations became public, New Life fired Haggard and he resigned as president of the national organization.
On Friday, New Life Church announced Haggard's relationship with the volunteer in a letter to the congregation.
In the last three weeks, Boyd said, the young man told him that he was considering going public with his story because Haggard was portraying himself as a victim in an upcoming HBO documentary called "The Trial of Ted Haggard," which is scheduled to air Thursday.
"I counseled him it wasn't going to help him or the church's healing. Plus it was in violation of the agreement we signed with them," Boyd said.
An interview with the former volunteer is scheduled to air Monday evening on KRDO-TV of Colorado Springs, Colorado. Haggard is scheduled to appear on CNN's "Larry King Live" on Thursday night.
The 2006 controversy involving Haggard erupted when Jones, the former prostitute, said the pastor had paid him for sex over three years and had used methamphetamine in his presence. Haggard said in interviews that he received a massage from Jones, but denied having sex with him. He also said he bought methamphetamine, but threw it away instead of using it.
The assertions received widespread news coverage and sparked charges of hypocrisy, particularly because Haggard had condemned homosexual sex in a documentary called "Friends of God."
In a settlement with New Life, the church and Haggard agreed that he would retain his six-figure salary for a year, leave the Colorado Springs area, receive counseling, and not speak publicly about what had happened for one year, according to a church staff member with knowledge of the settlement who was not authorized to speak on the record.
Jones said Monday that he has spoken with the former church volunteer whom Boyd said had a relationship with Haggard.
"My anger is so much at the church," Jones said. "They tried to keep this quiet when all along I've taken a beating feeling like I was the only one, when clearly there were others."
Despite the fresh scandal, Boyd said he is hopeful for the future.
"We've added 1,500 people in the last 18 months," he said. "We're trying to adopt 100 orphans into families in the church.
"We had a leader with flawed character and we're trying to clean up from the residue of the past. This will not always define us. I can promise you that in the days ahead, we won't be identified with scandal, but helping the widows and orphans."