Tens of thousands of dried caterpillars have been seized by border force officers at Gatwick airport.
The discovery was made after a 22-year-old man travelling from Burkina Faso via Istanbul was stopped.
A border force spokesman said: "Officers discovered the 94kg (207lb) of dried insects shrink-wrapped in cellophane, which had been packed into four hessian bags.
"The man claimed that they were for personal consumption and that they were to be used as food."
The insects were seized because they breach controls on the importation of products of animal origin.
Restrictions apply to products made from meat, dairy, fish, eggs and honey, as well as some fruit, vegetables and plants.
The spokesman added: "Following the detection, which took place on 23 February, the man was warned by officers about the restrictions on bringing dried insects into the country. The insects will be destroyed."
Ingrid Smith, from the border force, said: "This was an unusual seizure but the vigilance of our officers has stopped these dried insects from entering the UK, and possibly posing a risk to our food chain.
"I would warn travellers not to attempt to bring any products of animal origin into the UK without a permit, as they may not have been inspected to appropriate standards and may contain diseases."