The state medical board has indefinitely suspended the license of a family physician who admitted to having sex with two female patients -- including one relationship that spanned 20 years.

Dr. John A. Beall, who formerly practiced at the Allina Medical Clinic in Eagan, was cited for "unprofessional and unethical conduct" following an investigation by the Minnesota Board of Medical Practice.

In Minnesota, doctors are prohibited from sexual contact with patients. In recent years, the board has disciplined fewer than 10 doctors each year for sexual misconduct.

Among other things, Beall admitted to having sex with one patient during clinic visits, infecting her with a sexually transmitted disease and then treating her for it.

Beall, 57, was fired in December 2007 after the sexual relationships and other problems came to light, according to documents released by the board. Allina officials had no comment on the case, other than to confirm that he worked at the clinic until last year. The medical board issued its findings on July 12.

Beall could not be reached for comment. But he acknowledged the allegations "and apologized for his unethical conduct," according to a settlement agreement he signed with the board.

Beall admitted that he began a 20-year sexual relationship with one patient in 1984, when she sought treatment for a back injury, and that he continued to treat her with escalating amounts of narcotics through 2007, often with no documented reason.

In November 2004, he began treating another woman he had met a few months earlier on a "social networking" website, according to the board document. Over the next two and a half years, they had sexual relations during at least eight clinic visits, the document says, although he "denied that he pressured her to perform the acts."

Beall also prescribed several drugs to the woman without recording them in her medical record. One treatment was for a sexually transmitted disease that she got from him, he acknowledged.

The board launched an investigation in October after receiving a complaint about Beall's relationship with the two patients. He was also accused of accessing pornographic sites on the Internet at work, the board reported. He admitted the allegations and lost his job shortly afterward.

Beall, of South St. Paul, was ordered to undergo a "comprehensive evaluation" by a board-approved facility, and he may petition to have his license reinstated at a later date "upon submission of satisfactory evidence that he is fit and competent to resume practice." Until then, he is barred from practicing medicine in Minnesota.

Maura Lerner • 612-673-7384