A Republican state legislator who repeatedly voted against gay rights measures resigned his seat Wednesday amid revelations he had sex with a man he met at an erotic video store while in Spokane on a GOP retreat.

In a written statement, Rep. Richard Curtis, of La Center, said that while he believes he's done a lot of good during his time in the Legislature, "events that have recently come to light have hurt a lot of people."

"I sincerely apologize for any pain my actions may have caused," he wrote. "This has been damaging to my family, and I don't want to subject them to any additional pain that might result from carrying out this matter under the scrutiny that comes with holding public office."

Three days earlier, Curtis had insisted to his local newspaper that he was not gay and that sex was not involved in what he said was an extortion attempt by a man last week.

But in police reports, Curtis said he was being extorted by a man he had sex with in a Spokane hotel room. The other man contends Curtis reneged on a promise to pay $1,000 for sex.

House Minority Leader Richard DeBolt, R-Chehalis, said that as more "troubling" details began to emerge "it has become clear that he can no longer effectively represent the constituents who elected him."

His resignation was delivered to Gov. Chris Gregoire on Wednesday afternoon. A Republican successor will be chosen by county Republican leaders, and will serve until the 2008 election.

Numerous efforts to reach Curtis or his lawyer, John Wolfe, by phone have been unsuccessful.

Curtis, 48, told police he was the victim of an extortion attempt by Cody Castagna at the posh Davenport Tower hotel on Oct. 26, search warrant documents said. Castagna, 26, of nearby Medical Lake, told police that Curtis had agreed to pay him for sex, then reneged.

Curtis is married and has children, according to his legislative Web site. Elected to the state House of Representatives in 2004, he voted in 2005 and 2006 against a bill that granted civil rights protections to gays and lesbians, and in 2007 voted against a bill that created domestic partnerships for same-sex couples. Both measures eventually passed the Democratic-controlled state Legislature and are now state law.

Curtis was among state GOP lawmakers in Spokane Oct. 24-26 for a retreat to discuss the upcoming legislative session. He went to the Hollywood Erotic Boutique early on Oct. 26 and met Castagna, who accompanied him to the hotel, police documents said.

The two arrived at the hotel around 3:30 a.m. and had sex, after which Curtis fell asleep, according to documents released Tuesday.

Curtis alleged Castagna took his wallet and later offered to return it for $1,000. Curtis said he only had $200 and left an envelope with the money at the hotel desk, the documents said.

Police reports said Castagna allegedly called Curtis and demanded an additional $800, and threatened to expose Curtis. But Curtis had already contacted police, who listened to the call and then met with Castagna.

There have been no arrests in the case. On Wednesday, Spokane County Deputy Prosecutor Larry Steinmetz said a decision about possible criminal charges in the alleged extortion case was weeks away.

Castagna, who appeared Tuesday at a Spokane news conference with his lawyer, David Partovi, said Curtis gave him his wallet to hold as collateral "for the money that he promised me." Partovi refused to let his client tell reporters what he did for the money, noting Castagna had already spoken voluntarily with police.

"Cody Castagna admitted threatening to publicly expose Richard Curtis' gay lifestyle to his wife unless Richard Curtis provided the disputed money," the police documents said.

Partovi refused to let Castagna respond to a question about whether he threatened to "out" Curtis.

The lawyer noted extortion "is a violent Class B felony" and declared that his client "didn't do anything wrong, at that level anyway."

On Monday, Curtis told The Columbian newspaper of Vancouver, Wash., that he did not solicit sex.

"I committed no crime," he said. "I did not solicit sex. I was trying to help somebody out."

Curtis, a former firefighter, declared, "I am not gay."

In his initial statement to Spokane police on Oct. 26, Curtis admitted having sex with Castagna, but said he did not offer to pay for sex. He said he gave him $100 as gas money, but said he did not consider that paying for sex, according to the police reports.

Police reports said Curtis initially contacted a friend in the Washington State Patrol, in Western Washington, to investigate the case because he feared the Spokane authorities would talk to the media. But patrol officials referred the case to Spokane police.

The police reports added that Curtis told officers he only wanted his wallet back "and wanted to keep the incident as low key as possible." He did not want to pursue charges against Castagna, the report said.

The next day, police reports said, Curtis told a detective by phone that he was in Cle Elum because he had wrecked his car on the drive home.

Curtis also told the detective he "would have to tell his wife the truth and he would have to get a divorce attorney."