A 12-year-old boy was on the receiving end of some rather foul language when he tried out an iPhone 4S in a Tesco store, according to a report.

The Sun claims that the lad was told: "Shut the f*** up, you ugly t***.

Charlie le Quesne had merely asked the handset, a demo model in Tesco's Coventry store, how many people there were in the world, according to the report. 

However, as pranksters had tampered with the phone - setting the owner's name in as "Shut the f*** up, you ugly t***," - after it had told him the answer, it launched into the foul-mouthed tirade.

Charlie's mum Kim, a nursery worker, was less than impressed. "The phone was a demo version and was low enough on the shelf for Charlie to have a go with it. He asked it a simple question and we couldn't believe the filth it came out with. I thought I must be hearing things. So we asked again and the same four-letter stuff blared out," she told The Sun.

Tesco promised to investigate, while Apple hasn't commented on the matter.