Eton college pupils
400 families thought their sons were going to Eton... 391 found they weren'tGetty

Eton College has made a humble apology and launched an internal investigation after conditional offers of a place at the world-famous school were erroneously sent to the families of 400 boys.

A "systems" error was blamed for an email offering a conditional place to the elite college for September 2017 which was meant to be sent to nine families being sent to another 400, according to The Guardian.

"This error was discovered within minutes and each family was immediately contacted to notify them that it should be disregarded and to apologise," said a spokesman for the £34,000-per-annum school.

"We take this type of incident very seriously indeed and so a thorough investigation, overseen by the headmaster Tony Little and led by the tutor for admissions, is being carried out to find out exactly what went wrong and ensure it cannot happen again.

Boris Johnson
Boris Johnson and David Cameron are both Eton old boysReuters

"Eton College offers its sincere apologies to those boys concerned and their families. We deeply regret the confusion and upset this must have caused."

Prime Minister David Cameron and several members of his inner circle - including London Mayor Boris Johnson - attended Eton, which has become a byword for prestige - or, depending on your politics, of privilege.

The school, which was founded 575 years ago, has educated a total of 19 future prime ministers - and been the subject of a song by Paul Weller of The Jam, who attended a less privileged school in Woking.

Speaking about Eton last year then-education minister Michael Gove, who attended another fee-paying school, said the concentration of Old Etonians in the cabinet was ridiculous, and would have been unheard-of in any other developed economy.

This unbalance in government, said Gove, was "a function of the fact that... more boys from Eton go to Oxford and Cambridge than boys eligible for free school meals."