Some 800 tonnes of freight which fell overboard from a container ship in the Wadden Sea during bad weather in January has still not been recovered, infrastructure minister Cora van Nieuwenhuizen has told MPs.

The MSC Zoe lost 342 containers of goods, leading to a massive clean-up operation as plastic, toys and machinery were washed up on the shores of the Wadden Islands.

In total, 299 containers have been salvaged at a cost of €35m so far, with the ship’s owner picking up the bill.

The minister said  further efforts to use boats and divers to recover the goods would be pointless because the items have been spread over such a large area. Each search costs 2.5 litres of diesel for every kilo of recovered waste, the minister said in her briefing.

The MSC Zoe is one of the biggest freighters in the world and can carry 19,000 containers in total. It was heading from Portugal to Bremerhaven in Germany when the containers came loose in high seas.

The beach clean-up operation will last until mid 2020 and beyond if necessary, the minister said.

The coastline of the Wadden island of Schiermonnikoog, for example, remains polluted with plastic beading, and new waste continues to wash up every day.