The problem arises with a program called Secret Writer's Society, aimed at children aged seven to nine, which - to make matters worse - features a computer-generated voice.

The secret is out

The way it is supposed to work is that children undertake writing "missions" that help to develop creativity. The computer then speaks what they have written.

A filter detects inappropriate words - checking them against a built-in database - and blocks them. But in the version intended for use on Macintosh computers, the producers of the software say there is "a glitch in this filter".

Foul mouthed

As a result, "a small number of Macintosh systems may encounter a situation where the voice enunciates several of these prohibited words from the filter database while vocalising the child's text". In other words, the computer swears at the hapless infant.

The program is made by the Panasonic Interactive Media Company, based in Santa Clara, California.

It says the bug has been corrected and is offering a free replacement disk to owners of the foul-mouthed version.

The company was alerted to the unhappy state of affairs by the SuperKids educational software review. One of its users said the stream of abuse resembled "something out of a slasher movie".