(CNN) UK authorities seized almost 1.3 tons of heroin with a street value of £120 million ($148 million) from a container ship, in the nation's largest ever bust involving the drug.

Officers from the National Crime Agency (NCA) and the Border Force found the heroin hidden in a cargo of towels and bathrobes when the MV Gibraltar docked at Felixstowe on August 30, according to an NCA statement.

The 1,297 kilogram haul would sell for £27 million at wholesale prices, but its value would rocket to £120 million at street level, the NCA said.

The haul follows a 398 kilogram seizure at the port of Felixstowe in August.

"This is a record heroin seizure in the UK and one of the largest ever in Europe," said Matt Horne, NCA deputy director of investigations.

"It will have denied organised crime tens of millions of pounds in profits."

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