Toy giant Lego was forced to repackage 120,000 sets at a cost of £1.3million after one worker wrongly labelled pieces the wrong shade of grey.

The sets, which includes the best selling Star Wars models, were supposed to include dark grey Lego blocks.

But due to the mistake at the plant in Billund, Denmark, they were all packed with light grey pieces instead.

Toy giant Lego was forced to repackage 20,000 sets at a cost of £1.3million after one worker wrongly labelled pieces the wrong shade of grey (file photo)

Lego technicians traced the mistake to a single worker at the factory - and found they had wrongly labelled a production line tube.

The revelation emerged in Lego's own in-house staff magazine this week which carried a report on the 2015 bungle.

Although the company discovered the error before the sets hit retail stores, Lego had to call in holidaying employees from the Czech Republic and Hungary to repack the sets.

Lego, though, did not discipline the worker - but instead spent nearly £50,000 on improving lighting and labeling at the plant.

Despite the unnecessary spending, Lego recorded record high revenues of £3.9billion last year.