The Jewish Community Secondary School is mystified by a Department for Education statistic stating that nearly a third of its first intake last year spoke English as a second language.
According to a table in the DfE publication, Schools, Pupils and their Characteristics, of the 155 pupils who entered the new cross-communal school, 105 were native English speakers, while 50 grew up with another language at home.
Although the DfE says the data is supplied by the school, JCoSS head Jeremy Stowe-Lindner said that he was "not familiar" with the figure.
Instead, he said, the number of students now at the school who were classified as having English as an additional language (EAL) was 48 out of 346 - around 13.9 per cent. Of these, 32 were in the first year, and 16 in the second year.
"The biggest group within this is our sizable Israeli cohort," Mr Stowe-Linder said.
The others on the EAL register were mostly Jewish children from Europe, plus a few non-Jewish pupils including two from East Europe who are actually classified as "gifted" in English.
Overall, the school has nine non-Jewish children, all in the second year including two in the special autism unit. This year's entry includes no non-Jewish children.
According to the DfE data, 12.5 per cent of pupils at King Solomon High School in Essex have English as a second language: 10 per cent at JFS; 3.7 per cent at Hasmonean: 3.1 per cent at Yavneh: and 1.5 per cent at King David High School, Manchester.
Meanwhile, JCoSS said around 500 people attended an open evening for its sixth form, which will start with 40 pupils next autumn.