An Island woman has filed a civil lawsuit against Dr. Sjardo Steneker, alleging he used his position as her physician to “induce a romantic and sexual relationship” with her in violation of state law and the standards of appropriate medical care.

According to the suit, filed in February in King County Superior Court, Steneker failed to tell her that he was involved with other women at the time; promised that she and her children would always have medical care; and seduced her by “expressing his fantasies” about her.

The plaintiff is identified only by her initials, K.B., in the suit, which was filed by Seattle attorney Robert Zielke. She’s seeking an untold amount in damages, the suit says, to cover lost income and medical expenses stemming from the relationship, as well as pain, suffering and emotional distress.

But Steneker’s lawyer, Islander Bob Krinsky, said the suit amounts to a defamation of Steneker’s character and is factually and fundamentally flawed. The date when the relationship began, for instance, is not accurate; it started, he said, five months after her last visit with the popular Island physician.

“It’s a very important distinction, and I believe we’ll be able to prove this,” Krinsky said.

The suit comes at the same time that Steneker, a Dutch-born family practice doctor with a full practice on Vashon, is facing a state investigation for allegations that he engaged in a handful of inappropriate relationships with current and former patients, considered “unprofessional conduct” under state law.

According to a statement of charges filed a little more than a year ago, Steneker got romantically involved with four women in 2007 and 2008; three of them were patients or former patients, the state says; one of them, charging papers show, was the mother of two children who were patients of Steneker. Those charges were later amended to include allegations that Steneker got involved with two other female patients.

Steneker’s case is expected to come before a health law judge for a multi-day hearing beginning May 16, said Tammy Kelley, a case manager with the state Department of Health. Should he be found guilty of the state’s charges, he could get his license suspended for up to five years.

“He could face probation, but more likely he’d face time out of practice,” Kelley said.

Krinsky, Steneker’s lawyer, said such an outcome would devastate Steneker’s practice. “A five-year suspension would be a de facto destruction of his career,” he said.

The state’s case, like K.B.’s suit, he added, is fundamentally flawed. The state has alleged that a doctor cannot become romantically involved with a patient until two years after the physician-client relationship has ended. But according to Krinsky, that law applies to health care professionals; the law that pertains to physicians is much broader, calling for physicians to use a “reasonable amount of time” standard, Krinsky said.

“Dr. Steneker is an excellent doctor with a very familiar practice style, and it’s being used against him,” Krinsky added.