Three middle-aged men from the North-East have been arrested as part of a huge nationwide drugs bust.

The National Crime Squad today swooped on homes in Tyneside, Merseyside and Scotland, arresting at total of 13 people and smashing what is thought to be one of the country's biggest heroin rings.

The early morning raids were the culmination of a 12-month investigation to piece together a supply and distribution chain dealing in large quantities of the Class A drug and other controlled substances.

The investigation, codenamed Operation Ruin, also seized six kilos of heroin with an estimated street value of £1.6m from an address in Dublin.

This was made with the close co-operation of the Garda Siochana.

Before yesterday's arrests the probe had already resulted in the seizure of a large amount of drugs - including 16 kilos of heroin, 50 kilos of cannabis and 41 kilos of amphetamine. A irearm has also been recovered.

Det Chief Insp John Tyrer, of the National Crime Squad, said: "I believe yesterday's action has disrupted a major and organised heroin supply and distribution network - based in Liverpool, but spread all over England and Scotland. This illegal business had the potential to make millions from the drugs trade.

"This has been a lengthy and intensive enquiry which has shown how closely we can work with forces in a targeted approach to organised crime.

"We have already stopped massive amounts of drugs reaching the streets and now we have broken the chain which was ultimately putting them there."

All 13 people were arrested for conspiracy to supply class A and B drugs and were expected to be questioned at police stations across Merseyside by National Crime Squad officers in the coming days.

Those arrested were three men from Newcastle, aged 47, 53 and 50, six from Liverpool aged 41, 51, 19, 38, 40 and 37, a 31-year-old man from Cheshire, a man aged 44 from Glasgow and a man from Lanarkshire aged 36 who was arrested in Blackpool, Lancashire.