Stalking support services and police forces have recorded a surge in perpetrators turning to online tactics to harass their victims during the coronavirus lockdown.

Paladin, a national stalking advocacy service, and the Suzy Lamplugh Trust, which runs the stalking helpline, reported a surge in cyberstalking involving social media, messaging apps and emails in the first four weeks of the lockdown.

But the services and police warned there were still repeated examples of physical stalking despite the Covid-19 restrictions, including a case in which the perpetrator waited outside the victim’s isolating parents’ house when the victim dropped off essential goods.

Police forces took part in a nationwide stalking awareness week in April but the chair of Paladin, Rachel Horman, remains critical of the police response to the crime, saying: “They don’t take it seriously and that’s not changed since the lockdown.”

Horman, a solicitor who works on stalking and domestic abuse cases, said Paladin had seen a 40% increase in contacts from victims – both by phone and email – since the lockdown was imposed.

She said: “There’s still a problem because they feel more isolated than ever. They can’t reach out to their normal support networks, family, friends, etc, because obviously they’re locked down like everyone else.

“But stalking is still going on. Some people think that they’re safer now because people can’t go out the same. That’s not the case.

“The police unfortunately are still not taking stalking seriously, despite everything they say. The police will look at the incident in isolation without joining the dots together and looking at the whole picture.”

The Suzy Lamplugh Trust said nearly 1.5 million people in England and Wales are victims of stalking every year.

The trust said there was a drop in contacts to the helpline initially as people adjusted to home isolation, but this has risen “considerably” with one caller describing feeling like a “sitting duck”.

In cases recorded by the trust, stalkers have used the coronavirus as a threat. One person told others that her victim, who ran a cafe, had the virus and did not wash her hands, and another threatening to give their victim the disease.

The main stalking behaviours being reported to the helpline during the lockdown were unwanted phone calls, emails and text messages, and contacts over WhatsApp, Facebook and Instagram, the trust said.

Suky Bhaker, the chief executive of the Suzy Lamplugh Trust, said: “During the immensely difficult circumstances that many are experiencing amidst the Covid-19 pandemic, it is essential that victims of stalking are not forgotten and that essential services continue to support them.”

One police force, Nottinghamshire, reported a near doubling in stalking reports during the lockdown period, with 46 cases from 23 March to 19 April, compared with 24 cases during the same period last year.

Some victims in the force area have been forced to close down their social media accounts after stalkers targeted them – on average, 100 times before they contacted police.

The force has issued two stalking protection orders under the lockdown, with another one in the pipeline against a man in his 30s.

Katy Bourne, the chair of the Association of Police and Crime Commissioners, who was a victim of stalking, called on PCCs, police forces and criminal justice agencies to ensure that, despite the pandemic, they were still putting robust measures in place to keep victims safe.

Bourne, the PCC for Sussex, said: “Stalkers now have 24 hours in the day, uninterrupted, to obsess over their victims.”

A stalking advocacy service in Bourne’s force area, Veritas Justice, reported a 75% increase in cyber and online stalking activity.

Bourne added: “The rise in cyberstalking due to the lockdown concerns me deeply. We know all too well that this behaviour causes extreme distress and can unfortunately escalate quickly.

“The severity of risk to a victim is now defined by the amount of time invested by the perpetrator in their obsession. So, with many victims receiving over 100 text messages, emails, phone calls a day, we know that these strong fixations could have a more sinister outcome.”

Bourne said that when lockdown restrictions were eased, reports of physical stalking crimes were likely to rise as victims and their perpetrators have more freedom of movement, and there may be an increase in third-party reporting.

Bourne said she was concerned that interim charging protocols for the Crown Prosecution Service did not specify stalking as a priority offence.

“While not all stalking cases will reach a crisis point, research has proved that early identification of stalking behaviours is ultimately about homicide prevention,” she said.

• The UK national stalking helpline is on 0808 802 0300.