Being in a cartel is unlawful and is a risky business – especially when one of the cartel members blows the whistle on the others.

In such circumstances, the whistleblower can receive immunity from punishment, leaving the other members to carry the can – albeit that with full cooperation with the authorities, a reduction in the penalties levied will normally apply.

When a member of a cartel which controlled the prices paid for second-hand car batteries informed the authorities of the existence of the cartel, it was granted lenient treatment to the point of total immunity from punishment.

The other three cartel members were fined an average of €22 million each. The whistleblower avoided a fine of more than €38 million.

While a cartel arrangement covering a whole industry across Europe may be relatively rare, collusion on a local or local industry scale is more common and is also unlawful.