The American School in Japan, one of Tokyo’s most prestigious international schools, has revealed that teacher Jack Moyer, a renowned marine biologist, sexually abused students while employed by the institution between 1963 and 2000.

School executives made the admission to alumni in an email sent out Monday. However, numerous former staff and students allege that ASIJ administrators had been aware of the molestations for decades — and failed to act on victims’ complaints.

Moyer committed suicide in Tokyo in 2004.

The email sent to alumni by Stephanie H. Toppino, chairwoman of ASIJ’s board of directors, and Head of School Edwin V. Ladd stated: “This past November, we received a letter from a former ASIJ student detailing sexual abuse by a former ASIJ teacher, Jack Moyer. Based on other information we have been able to gather, as well as an acknowledgement made by Moyer to another affected student prior to his death in 2004, we believe he engaged in inappropriate sexual contact with students during his teaching tenure at ASIJ.”

It was not immediately clear why the school delayed contacting alumni for four months after receiving the letter in November.

Furthermore, a number of former staff and students reacted angrily to the email’s implication that the school had only recently discovered Moyer’s abuse.

Janet Simmons, who says she was abused by Moyer after enrolling in ASIJ as an 11-year-old in 1970, told The Japan Times that she had first made school officials aware of the alleged crimes in 1990.

“Much to my disappointment, they did not contact me nor did they cease to elevate his stature in the community. Had they (acted), many girls may not have suffered from his abuse,” she said.

Simmons says she repeated her allegations to ASIJ officials in 2000, but the school still did nothing to notify parents or children. In 2009, she detailed the circumstances of her abuse in a blog titled “Thank You For Holding My Hand.”

Another former ASIJ student, speaking to The Japan Times on condition of anonymity, said she witnessed Moyer receiving oral sex from a female student in 1979. She said she reported what she had seen to the school principal and school counselor, but she believes they took no subsequent action.

According to the former student, who said she has been in contact with many fellow alumni, Moyer molested at least 32 young girls during his employment at ASIJ.

Additionally, former student Tim Shorrock said he witnessed Moyer touching two 13-year-old females inappropriately during a school trip to Chiba Prefecture in 1964. He recalled “thinking something is very wrong here. He’s a grown up, and they’re my age. Why is he doing this?”

Like Simmons, Shorrock believes ASIJ officials were aware of Moyer’s abuse for many years.

“They knew about it and never lifted a finger. There is no doubt in my mind there was a cover-up, and that’s something the school still needs to answer for,” he said.

A longtime ASIJ teacher and former colleague of Moyer who asked that his name not be published due to continuing connections with the school told The Japan Times: “This is a blight that has been hidden. It is a horrendous cover-up that all the administrators of the ’60s,’70s and ’80s knew about.”

Approached for comment on allegations that school officials had been aware of Moyer’s crimes for many years, board Chairwoman Toppino told The Japan Times, “ASIJ has communicated all that it will say publicly on this matter in the letter sent to our community this past Monday.”

In an apparent move to discourage alumni from speaking to the media, the officials’ initial email had requested that alumni with information contact the school directly “(t)o ensure that any communications are both accurate and respect the privacy of our community.”

Founded in 1902, ASIJ bills itself as “Tokyo’s Leading International School,” with campuses in Roppongi and Chofu. According to its website, it currently has 1,500 students ranging from nursery age to grade 12 from 40 nationalities. Its alumni include U.S. Sen. John Cornyn, Sony President and CEO Kazuo Hirai and pop star Hikaru Utada.

Moyer worked as a middle school teacher at ASIJ from 1963 to 1984 and a consultant to the school’s marine science programs until 2000. He was a well-known expert in marine biology, particularly in the waters surrounding Miyake Island, a volcanic islet 180 km southwest of Tokyo on which he owned a house.

Moyer led ASIJ students on weeklong study trips to the island. During these trips, it is alleged, he abused a number of female students.

Commentators on an open Facebook community group for 1970s ASIJ alumni this week portrayed Moyer as a sexual predator who chose his targets carefully.

He appears to have focused on young American girls — vulnerable due to being so far from their home country — and groomed them with compliments and gifts.

According to Simmons, “Jack was also a very skilled manipulator. He was very delusional. He didn’t believe he was doing anything wrong.”

Moyer apparently fooled many people. In 1996, he was awarded a prize from the Asahi Shimbun for his marine conservation efforts and work with children. While in 2000, Victor Entertainment released a CD of the biologist — calling himself “Papa Jack Moyer” — singing jazz covers. It was titled “Chikyuu no Kodomotachi E,” (“To The Children of the Earth”).

That same year, Moyer was forced to evacuate to the mainland following a volcanic eruption on Miyake.

Four years later, he committed suicide at the age of 74. According to his obituary in the Mainichi Shimbun, his body was discovered lying on his futon next to two bottles of beer and a large number of unidentified pills.

In its email on Monday, ASIJ officials sought to reassure alumni of the safety of children currently at the school.

“We also take this opportunity to assure our community that ASIJ is a school committed to sustaining an environment that does not permit or condone any form of sexual abuse, sexual harassment, or any abuse of children by adults,” it read.

It also told alumni that it will “continue to review policies and practices as they relate to the protection of students.”

Such reassurances appear to have split alumni.

Former student Shorrock said they ring hollow.

“ASIJ needs to go far beyond this statement and hire investigators to determine how Moyer’s crimes were covered up and who is responsible. Until this, it is only an exercise in PR,” he told The Japan Times.

On the other hand, Simmons believes ASIJ has adopted sufficient policies to prevent such a problem from recurring.

She also expressed hope that, by speaking out, her testimony will benefit the ASIJ community.

“Sharing my story has helped others recognize questionable relationships. I think the more we talk about it — and share how manipulative these perpetrators are — then hopefully we can all see how to help prevent this from happening to other children,” she said.