Having spent thousands of dollars registering his 6-year-old son at BPK Penabur International School in Kelapa Gading, North Jakarta, in 2008, businessman David Wongso was expecting to see his son's education handled by professionals, he says.

However, David began to question the school's credibility over the next few months when he found extensive English grammatical errors in his son's worksheets from the school.

"Initially I just thought it was typos, but when I saw similar mistakes happening again over the following days I realized there could be something wrong with the quality of the school's teachers," he said.

David was among three parents who reported the 60-year-old BPK Penabur institution last year to police for deception.

After registering his son at the institution's newly opened international school, David said he had felt deceived at information presented in the school's promotional leaflet and magazine advertisement.

According to the ad and pamphlet, the school held a license from Cambridge University to apply its international curriculum. While the school did employ several native-English-speaking teachers, the claim about the license was not true, he said.

"After we checked the school's status with the Cambridge representative for the Asia-Pacific region, we were surprised to find that it hadn't got their official license yet," he said, adding that he and 17 parents of first-grader students had subsequently requested the school return their money.

David had spent a total of US$5,700 (S$8,048) - comprising $3,000 for an entrance fee and $2,700 for 9 months' tuition.

The request, however, was rejected, forcing most of the parents to keep their children enrolled at the school.

It was only David and three other parents who finally moved their children to another school in early 2009.

BPK Penabur chairman Robert Robianto, however, said it was impossible for the school to return the parents' money because it was their decision to register their children at the school.

He also denied allegations that the school had no license to run a Cambridge-based curriculum, saying it had secured a license for their international school in Tanjung Duren, West Jakarta, in 2006.

"We also secured [a Cambridge] license for our international school in Kelapa Gading," he told The Jakarta Post.