CUSTOMS officials last night threatened to seize boats travelling to an offshore off-licence anchored 13 miles out in the North Sea.

Customs and Excise officials have already launched an investigation into Philip Berriman's maritime business venture off the coast of Hartlepool.

The marine engineer is selling cut-price alcohol and cigarettes from his 72ft yacht, Rich Harvest.

Mr Berriman says a free boat running out to his duty free shop is fully booked for the next two months. Charter boats working out of Hartlepool have also been fully booked.

The entrepreneur said: "All the charter boats are taking people. A bus turned up on the quay the other day. With waves breaking over the quay, it still turned up."

His customers can expect to pay between £15 and £23 for a carton of 200 cigarettes and between £5 and £6 for a bottle of spirits.

But a Customs spokesman said last night: "Customs are looking at this matter.

"We want to alert members of the public that if they purchase alcohol or tobacco in these circumstances their goods and boats are liable to be seized.

"Any person simply travelling outside the 12-mile limit and purchasing either duty free or EU tax paid goods are not entitled to any allowances.

"Therefore, any goods acquired by an individual in these circumstances may be seized, along with any vessel being used to transport the goods into the UK."

With his business partner, a university lecturer in maritime law, Mr Berriman says he and his floating off-licence are safe.

He says he is using a loophole in law which applies only to alcohol and cigarettes bought from an EU state or a country outside the EU - not bought in international waters.

As long as that loophole remains open, Mr Berriman says Rich Harvest will be trading.

He said: "As long as it takes, we will keep on. We are going to milk it as long as we can.

"It's going to take some time.

"Present legislation does not apply. There is nothing they can do."

He added: "It's been pretty quiet because of the weather, but we have stacks of people wanting to come out."

The Customs spokesman said: "For travel within the EU there is no duty free entitlement - this ended in 1999.

"Excise duty applies to any alcohol or tobacco brought into the UK, subject to any exemptions or allowances that may apply.

"A person is not entitled to bring any duty free goods into the UK unless they have personally travelled with the goods from a country outside the EU.

"Neither can a person bring in goods duty paid from another member state unless they have travelled personally with the goods from that member state."