The return shipping of the waste is to be paid for by the UK, the Polish police added.
An investigation into the waste’s source is still underway, conducted by the City Police of Elbląg and the Environment Agency.
An Environment Agency spokesperson said: “The illegal export of waste is a crime and we will not hesitate to take action against those responsible with offenders facing either a two-year jail term and an unlimited fine.
“We are working with the Polish authorities to investigate the circumstances around these particular exports and will take appropriate action to hold those responsible for the exports to account, should there be any evidence of wrong-doing, and ensure any illegally exported waste is repatriated to the UK.”
The City Police of Elbląg say 70 tonnes of the waste is already on its way back to the UK, although letsrecycle.com has not had this confirmed by UK sources. Another 150 tonnes are expected to follow, the police said.
According to the Polish police statement, 150 tonnes of stored waste was found in spring 2018 at a landfill site in the village of Bogaczewo, 72 miles from the port city of Gdansk.
The waste contained cardboard drinks packaging, aluminium foil, fragments of caps, paper and more, which investigations suggested was from the UK.
Two containers with similar contents – believed bound for the Bogaczewo site – were intercepted by police officers at the port of Gdynia.
And, following further surveillance, a truck from the UK containing more waste was detained as it tried to enter the landfill site.