Just months after a sex abuse scandal shook elite gymnastics to its core, another appears to be brewing in the world of taekwondo.

At the center are brothers and Olympians Steven and Jean Lopez, who are accused of having sexually assaulted multiple women.

According to USA Today, the brothers were first accused of sexual misconduct more than two years ago, but the inquiry, being run at the time by USA Taekwondo, was put on hold for unclear reasons as the two prepared to participate in last summer's at the Games in Rio de Janeiro. Steven Lopez, a two-time Olympic gold winner, competed in Brazil in the 80-kilogram category, but failed to medal, while his older brother Jean, meanwhile, remained his coach.

The accusations did not go away, however, and earlier this year, USA Today reports, USA Taekwondo's investigating attorney Donald Alperstein contacted the FBI.

Alperstein made the decision to go to law enforcement, he said in a March 22 letter obtained by the newspaper, "because so much of the misconduct occurred in multiple jurisdictions." He also said, according to the letter, that he "felt the Lopez brothers needed to be removed from the sport."

It's unclear exactly how many women the brothers allegedly abused, but according to USA Today, at least four women have come forward with complaints. One is former Olympian Mandy Meloon, who told the paper she spoke with the FBI, which would neither confirm nor deny the investigation, about "stuff that happened on the national team when we traveled internationally."

In a petition posted to Change.org two years ago that sought to bar Jean Lopez from the sport, Meloon detailed her experience, writing that the older Lopez brother began abusing her as a minor while she attended a junior camp at the Olympic Training Center in 1994 when she was 13. She said the abuse continued until she left the team at age 27.

"He started sexually harassing me at that camp, and it continued in the form of sexual assault, physical assault, verbal abuse, mental, emotional abuse, exploitation, slander, forced labor, stalking, blackmail and the loss of my spot on the last 4 Olympic Taekwondo teams," she wrote, making no mention of Steven Lopez.

She added at the time: "The abuse continues today."

The brothers, however, deny the allegations.

"I've never been inappropriate with anyone," Jean Lopez told USA Today, while his brother said he's "never" sexually assaulted or engaged in any untoward sexual behavior with his accusers.

Steven Lopez, 38, is one of the sport's most famous stars, having won five world championships and three Olympic medals. He took home top honors at the 2000 Olympics in Sydney and the 2004 Olympics in Athens. He later earned a bronze at the 2008 Olympics in Beijing.

Jean Lopez, 44, never achieved the same greatness in the sport as his brother, but he did take home a silver medal at the 1995 Taekwondo World Championships. Since then, he has found success coaching his brother and other members of the U.S. Olympic team in every Games since 2004.