Food imported into the U.K. through Brexit border posts is being sent back to Europe to be tested due to a lack of laboratory capacity in Britain, food bodies have said.

The Guardian reports that the SPS Certification Working Group, which represents 30 trade bodies covering £100bn ($128 billion) worth of the U.K.’s food supply, has written to the U.K. government warning that some samples of imported foods are being sent to countries such as Germany to be tested before they can be released at the border.

The lack of lab facilities is causing extra costs, longer delays and a shorter shelf life for food coming into the U.K., the group said.

The warning comes three months after the government introduced new post-Brexit checks on animal and plant products coming into Britain.

The checks at border control posts situated near U.K. ports, which were brought in on 30 April, aim to enhance Britain’s biosecurity and stop the introduction of diseases into the U.K. from the continent.

In some cases, these checks require samples of food being taken to be tested in labs for microbial or chemical analysis, or to check the authenticity of a product.

However, the U.K. is now facing a shortage in laboratory capabilities and is more reliant on international partners for help with sample testing.