Peddling crack cocaine and heroin to some of the most needy people in the city, the dealers made life hell for people living in certain neighbourhoods.

Dealers would stalk areas where they knew addicts hung out, offering to fuel their cravings.

Runners carrying the bounty of drugs to customers would blight neighbourhoods.

Today, 17 dealers are serving a total of 51 years and four months.

The biggest sentence was handed to Ian Gordon, who had two previous convictions for selling hard drugs, while others had a history of criminality.

Michael Holowienka had served time for his role in the infamous gangland killing of Pat Moore, when he was caught by the police sting on the city streets.

He is now starting a 21-month prison sentence.

Some escaped jail, after the courts ruled they were selling drugs simply to finance their habit, but now have tough community orders with monthly visits to Peterborough Crown Court as Judge Nicholas Coleman keeps a close eye on them. Suspended sentences loom over them.

They know any foray back into the murky world of drugs will see them locked up.

Many of the dealers came from outside the city, eager to make easy money by taking advantage of the higher rates paid for drugs in Peterborough.

Joel Mativat moved to the city to set up business, as did Tyrone Harris. Both were given lengthy sentences. Runners Selaatin Tilim and Ozgur Ozdemir were sent up from the east end of London to sell drugs.

Today, the detective who led the three-month operation – codenamed Abolish – vowed to catch any dealer who tries to move in to the city.

Detective Sergeant Dave Pike said: "These people were all coming up from other areas of the country to ply their trade in the city which is the worrying thing.

"It's the accessibility of the area, there is a lot of competition in London, so they know they can make more money up here.

"Drugs are cheaper in London, so for the price of a quick train journey up here they can make much more money.

"It just shows how into drug dealing they are, it's a business to them. It has to be commercially viable to them to keep coming up here

"A lot of the names have come up before, it's not just people caught up in a little thing, they know what they're doing now. Some might have drug habits but most are in it for the money.

"They couldn't care less who they sell drugs to."

As test purchase officers began infiltrating the seedy drug communities in May last year, they were drawn to St Theresa's homeless shelter in Manor House Street, in the city centre.

But DS Pike was keen to point out that it was the dealers persistence to sell drugs that led them there, rather than the centre being a magnet for drugs.

He said: "St Theresa's provides a service to people who need it, there is a reason why it's there.