Millions of pounds worth of heroin which was hidden in a spare tyre has been seized by Customs and Excise officers.

Four men, two British and two Slovenian, were arrested in the armed operation at Thurrock services on the M25 in Essex.

Officers recovered more than �8m of heroin at about 2200 BST on Wednesday, a spokeswoman for HM Customs and Excise said.

The arrests came after two men were seen transferring a spare tyre filled with 70 kilogrammes of heroin from the back of a Slovenian-registered lorry to a British-registered van.

Men questioned

The spokeswoman said: "Customs and Excise officers with armed officers from Essex Police observed surrounded four men at Thurrock Services and arrested them.

"They were taken to an east London police station and held overnight for questioning.

"It was an unusually large amount of heroin to be hidden in this way and had a street value of more than �8m."

Officers also later recovered a firearm and another weapon, after searching the two vehicles and an address in north London.

'Meeting point'

It was confirmed by the spokeswoman that Customs and Excise officers had made drugs seizures at Thurrock services in the past.

She said: "We can confirm that it is not the first time that this particular meeting point has been used for drugs trafficking, mainly because it is placed on a major motorway that allows access to the channel ports and to the rest of the country."

The Slovenian-registered lorry had travelled through the Channel Tunnel on Wednesday.