Travel cots were designed to be used with the original mattress and this should not be changed, the market surveillance directorate within the technical regulations division of the Malta Competition and Consumer Affairs Authority said.

The directorate said that mattresses in travel cots tended to be thinner and harder than those in normal cots. The mattress which comes with the travel cot was the key component to help keep the cot stable and, as such, using a different mattress might alter the balance, making it easier to tip over.

In most cases, changing the travel cot mattress also reduced the distance between the mattress and the top of the cot, which should be at least 50cms.

Adding a second mattress or changing it would also increase the chance of the child getting trapped between the mattress and the sides of the cot, posing a suffocation risk.

Zips on a travel cot should not detach easily and when possible should be avoided completely as these posed a choking hazard, the authority added. Travel cots with wheels should preferably have two wheels and two legs - so the cot cannot roll inadvertently - or should have wheels that lock properly.