The crisis at the Jakarta International School (JIS), which began with public allegations in April that the cleaning staff assaulted a six-year-old boy, has rocked an institution that has been a favourite with expatriates in the capital for more than 60 years.
The cleaners will be indicted on Tuesday and Wednesday but deny any wrongdoing, a lawyer for two of them said. All of them who previously confessed now plan to recant, claiming police beat them up, he said.
Since the first allegation emerged the scandal has snowballed, with more parents making abuse claims, school staff members accused and a revelation that a suspected serial paedophile sought by the FBI taught there for a decade.
Abuse claims have been made against Canadian Neil Bantleman, an administrator at the school, and Indonesian teaching assistant Ferdinand Tjiong.
The school has denied the accusations, and commissioned an investigation that it said showed no evidence of the alleged abuse. The pair have been in custody since mid-July while police investigate their cases.
The family of one boy allegedly abused has filed a civil suit against the school seeking $125 million in damages.
One of the cleaners, Agun Iskandar, will be indicted in at the start of his trial on Tuesday, while the four others will be formally charged Wednesday, according to officials at the South Jakarta District Court.
However Saut Irianto Rajagukguk, a lawyer representing Iskandar and another cleaner, Virgiawan Amin, said four of the cleaners would recant their confessions.
The fifth, a woman, never confessed, he said.
"The accused never committed the alleged rape," he told AFP. "The police beat the men so badly that they had no choice but to confess."
The lawyer also said medical examinations on the boy showed no signs of sexual abuses.
Police have repeatedly denied that they beat the cleaners.
A sixth cleaner, Azwar, who like many Indonesians goes by one name, was implicated in the case but died in police custody. Police say he committed suicide by drinking floor cleaning fluid.
The abuse scandal at JIS, a favourite with the children of foreign businessmen, diplomats and wealthy Indonesians, also sparked soul-searching about the high incidence of sexual abuse at the country's schools.