One of the world’s biggest cruise operators, MSC Cruises, has been told to stop using some adverts in the Netherlands because the “green” claims are misleading, the Dutch advertising standards authority said on Wednesday.

The RCC looked into seven television adverts, social media posts and website pages published by the company, which is based in Switzerland, following complaints by campaign groups.

The agency says companies must be able to back up claims about their green credentials with facts and figures. This means MSC can no longer assert that bio-LNG will have a significant role in the future, that LNG is a clean fuel for ships in the first place and that it is making major advances in being a net zero greenhouse gas emitter by 2050.

In addition, the RCC says, terms such as “environment-friendly”, “green” and “clean” say relatively little without further specifications so the “consumer can form their own few on an advertiser’s sustainability targets and efforts”.

RCC rulings are not binding but if they are not followed up on, the organisation can ask the consumer association ACM to impose a fine. MSC has already removed several statements.

Environmental activists in the Netherlands have turned their attention to cruise ships in recent weeks, and have blockaded the sea locks at IJmuiden to stop them reaching Amsterdam.