The Justice Department has started an investigation into a self-described self-help group in which women were branded with a symbol containing its leader’s initials, several people contacted as part of the inquiry said.

Those people said that agents with the Federal Bureau of Investigation had recently contacted or questioned them about the group, which is called Nxivm. They spoke on the condition of anonymity because officials asked them not to discuss the inquiry, which appears to be at an early stage.

In a related move, Gov. Andrew M. Cuomo of New York is expected to soon recommend possible changes in how state regulators review complaints against doctors, a spokesman said. The decision follows the disclosure that health department officials declined to act on complaints about two doctors affiliated with Nxivm, including one who reportedly used a surgical device to brand women. Inquiries into those two doctors are now underway, a spokesman for the governor said.

John Marzulli, a spokesman for the office of the United States attorney for the Eastern District of New York, which is reportedly leading the inquiry, said he could neither confirm nor deny whether an investigation into Nxivm, which is based in Albany, was underway.

The developments follow an October article in The New York Times that disclosed how some women who joined a secret sorority within Nxivm were branded with a symbol that incorporated the initials of the group’s leader, Keith Raniere.

Women were also told that compromising information they had provided to join the sorority, such as naked photographs, would be publicly released if they disclosed its existence. The sorority revolved around “master-slave” relationships, former Nxivm members said, in which women faced punishments, including physical ones, for not following a master’s order.

Since the late 1990s, over 16,000 people have enrolled in courses offered by Nxivm (pronounced Nex-e-um), which the group says are designed to bring about greater self-fulfillment by eliminating psychological and emotional barriers.

Most participants take some workshops, like the group’s Executive Success Programs, and resume their lives. But other people have become drawn more deeply into Nxivm, giving up careers, friends and families to become devoted followers of Mr. Raniere. Critics and former members have described the group’s practices as cultlike.

Mr. Raniere, whose followers refer to him as “Vanguard,” urges women to follow near-starvation diets of 500 to 800 calories a day to achieve the body shape he finds appealing. Some women who have followed that diet have stopped menstruating and lost hair, according to former Nxivm members.