Fraudsters are posing as nurses on dating sites as they seek to take advantage of the coronavirus pandemic.

National Crime Agency (NCA) director general Lynn Owens said online shopping fraud is up 46% since the lockdown, "making it one of the biggest growth areas in crime", with Covid-19 now linked to around 3% of all scams reported.

Criminals are playing on people's fears, offering fake or non-existent items for sale, including game consoles, personal protective equipment (PPE), medicines, hand sanitiser, and even puppies, she told reporters on Thursday.

"We've even seen reports of a dating fraud where people are pretending to be... a nurse in a hospital and say, 'I need money to help me to get to work', and abuse people that way," she said.

Investigators also fear organised crime gangs could try to exploit the Government's financial stimulus package.

The NCA is working with the Cabinet Office, the Department of Work and Pensions (DWP) and HMRC to identify fraudulent claims being made.

Ms Owens said production of cocaine in South America and heroin in Asia has continued "almost unaffected" by Covid-19, but restriction of movement rules has allowed the agency to intercept large batches.

The NCA was involved in the seizure of some 25 tonnes of Class A drugs around the world last month, including two tonnes of cocaine off the coast of Panama, another four tonnes off the coast of Spain and Portugal, and hundreds of kilos of heroin in Afghanistan and Pakistan.

Ms Owens said: "Restrictions have meant fewer opportunities for criminals to move drugs in smaller, more discreet amounts, especially through passenger traffic, which in turn means they've had to take more risks and move more drugs in bulk.

"Criminals may believe that authorities are distracted, particularly at ports, and think there is an opportunity to import larger quantities. We have shown this is far from the truth."

Seizures at the border included a quarter of a tonne of cocaine at Dover on May 5 found hidden under a load of medical dry ice, which was falsely addressed to a north London hospital.

Investigators have made more than 130 arrests for serious organised crime-related offences and seized more than £15 million pounds in suspected criminal cash during the Covid-19 lockdown.

There has been an increase in firearms seizures, with 39, including semi-automatic weapons such as Skorpion submachine guns and an AK47 assault rifle, over the last eight weeks.

The NCA is also targeting paedophiles, with 46 arrests linked to child sex abuse, including a man in his 30s, who allegedly pretended to be a teenage girl, inciting more than 100 young victims to send him images so he could blackmail them.

Investigators expect a rise of reports in child sexual abuse carried out during the lockdown as restriction of movement rules are eased.

And criminals are predicted to look to exploit opportunities to import drugs and illegal migrants to the UK.

Ms Owens added: "We assess that there is a strong likelihood that organised crime groups will seek to exploit professionals such as lorry drivers or port or airport or workers, many of whom may be more financially vulnerable, as a consequence of the lockdown and their loss of work.

"We have issued an alert to ports and airport operators reinforcing the need for staff to report any approaches or suspicious activity."