More than half the drug lines into Norwich and Norfolk have been stamped out by officers in the past 12 months, a police boss has revealed.

And the leader of Norfolk Police's county lines operation added reports of drug-related crimes will go down in 2022 now that significant arrests have been made.

She said that there are now under 30 drug lines into Norwich and Norfolk compared to 75 in November 2019.

Fewer than 10 of these still in operation are classed as the highest harm drug lines where factors are identified such as exploitation of children and indications of weapon carrying.

The term county lines describes illegal drugs being transported from major cities such as London to smaller cities and town across the country, in which children or vulnerable people are coerced into the operation by gangs.

A freedom of information request submitted to Norfolk Police shows there were a total of 175 arrests in connection with county lines across Norwich in 2021.

The month of March saw the most arrests during the year with 24, while April had the fewest with four.

Detective chief inspector Sonia Humphreys said: "During 2021 we were fixated on those with the highest harm and we have been focusing on those exploiting and coordinating activities.

"We are starting to see more meaningful arrests. Back in 2016, if there were episodes of street dealing it may have taken several months to get those cases through to court."

But DCI Humphreys stressed police are making use of technology and public intelligence to keep the numbers of criminals on the streets down in 2022.

"We are always scanning for Norwich threats and we can't just assume what will be in front of us," the county lines expert continued.

"We can't rest, sit back and think this is the only threat coming. We carefully work with our own department and the public."

She referred to the success of the government's project ADDER which combines targeted and tougher policing with enhanced treatment and recovery services in partnership with local organisations.

The programme is set to run until March 2025 and the government has pumped millions of pounds into the scheme.

DCI Humphreys said a "holistic approach" has been key in supporting people who are struggling from drug exploitation.

She emphasised police are unable to tackle the scale of the crime on their own.

She added: "The new drug strategy over the last three weeks was somewhat overshadowed by Plan B and Christmas parties that should not have done.

"But the government announcement is otherwise what we have been doing in Norwich and Norfolk for some time, focusing on exploitation and proactive support to get people the treatment they need."

Project ADDER identified Norwich, along with Blackpool, Hastings, Middlesbrough and Swansea Bay, as the hardest hit areas for county lines in England and Wales.

DCI Humphreys said the majority of the offenders in Norwich are coming from the south, not only from London, but also surrounding areas in Essex and Thames Valley.

She added: "We are seeing some from the Merseyside area but on a much lower scale compared to southern areas.

"Interaction with a national coordination centre allows everybody to focus and prioritise specific issues around drugs and modern day slavery."

Police have identified associated knife crime with county lines activities across the city.

DCI Humphreys said: "From a criminal justice point of view we are not lenient when it comes to the carrying of knives and we will seek prosecutions to reassure communities.

"We will not tolerate knife crime in the county and Norwich."

The FOI data for 2021 shows there were five county lines arrests across Norwich in January, 16 in February, 24 in March, four in April, 12 in May, 20 in June and 10 in July.

The number of arrests remained at similar levels throughout the rest of the year with 19 in August, 18 in September, 15 in October, 19 in November and finally 13 in December.