During the first five months of the year, Sweden's National Food Administration (Livsmedelsverket) was made aware of 138 cases within the EU of food imported from China that was not fit for consumption. By the same time last year the figure had reached 88.
Examples included food containing banned colouring, antibiotics, preservatives or pesticides. There were also cases of illegally imported, unclean or foul-smelling food, as well as products with high levels of heavy metals, poisonous mould and dioxins, reported Svenska Dagbladet.
The rise is said to highlight the disadvantages of food products being checked at the EU's outer borders. Tests for additives such as vitamins and minerals are rare.
"There's no doubt that food imports from China are a big problem," said Helena Storbjörk at the National Food Administration.
"We have good checks for animal imports from China, which are largely banned, and a far-reaching programme of checks for a whole range of vegetables. Unfortunately there's a lot of illegal importing which avoids all the controls," she said.
According to the National Food Administration there have been no cases reported in Sweden.