Police have apologised for not properly investigating obscene phone calls made to a BBC journalist.
Lucy Manning, a special correspondent with the corporation, says she spent more than two years battling to make the Metropolitan Police and Lancashire Constabulary take her case seriously.
During the phone calls, the unknown male caller appeared to be masturbating as he made lewd comments about Ms Manning.
She immediately informed police and passed on evidence, but at one stage officers dropped her case, forcing her to threaten to appeal in order to get it reopened.
Ms Manning says she was determined to persuade police to keep investigating because obscene phone calls can be a "gateway" crime to more serious sexual crimes, and she feared for other women.
She alleges that the officers' slow approach had allowed the suspect - previously convicted for public nuisance after making thousands of "dirty" calls - the chance to destroy evidence.
Ms Manning, who has reported extensively on violence against women, including the case of Sarah Everard, said her "eye-opening" ordeal showed how, despite promises of reform, women are still being failed because of police incompetence.
She has revealed her experience as police are under intense scrutiny for their allocation of resources after Essex Police established an investigation unit of a structure normally reserved for major crimes to probe a single tweet sent by Allison Pearson, the Telegraph journalist.
In October 2022, Ms Manning received a series of phone calls from an unknown number.
"Without a doubt, this stranger was masturbating down the phone," she told BBC News.
"The noises got louder and louder. My heart raced, struggling to believe what I'd just heard. I hung up. But the phone rang again and again."
She later picked up and recorded the call, which lasted for about five minutes.
"I was concerned about my personal safety," she said. "If this man knew my first name and number, did he know me?"
She dialled 999 and attended her local police station the following day to report the crime and provide the audio evidence.
Ms Manning then suffered repeated missteps and delays, firstly from the Metropolitan Police, to whom she initially reported the crime, and then Lancashire Constabulary.
Two months to identify caller
The Lancashire force took over the investigation after the Met had finally identified the withheld number and a person connected to it - Amjad Khan, from Blackburn - two months after the complaint was made.
She said the Met appeared not to realise that they should have asked the phone provider, EE, to investigate the withheld number, after an officer told her she should make the request.
Lancashire Constabulary then repeatedly told Ms Manning that there was "no need to arrest" the suspect because a voluntary interview was preferable, but that each time they visited his home no one had opened the door.
It was around this time that the journalist was covering the case of Wayne Couzens, the serving Metropolitan Police officer who abducted, raped and murdered Sarah Everard in 2021. It emerged Couzens had previously committed less serious sexual offences which, experts say, should have acted as a "red flag" but which police failed to investigate.
In March 2023, Ms Manning was informed that Lancashire Constabulary was dropping the case because Khan had claimed he had lost his previous phone, and without more evidence they could not charge him.
She threatened to appeal against that decision and was later informed that the force had carried out a Victim's Right to Review on her behalf and would reopen the case.
Eventually officers established that the suspect's current phone was the device on which the call had been made.
However, despite consistent prompting by Ms Manning, a further three months elapsed before Khan was arrested.
It was not till December 2023, 14 months after the calls, that Khan was charged with an offence of malicious communications by sending an offensive, indecent or threatening message."
"Apologies it's dragged on, but we got there in the end," an officer told Ms Manning.
Thousands of previous obscene calls
Khan finally appeared for trial at Lancaster magistrates' court this month, where he claimed that another person must have used his phone to make the obscene phone call.
He was found guilty but will not be sentenced for a further two months.
Ms Manning subsequently discovered an article in the Lancashire Telegraph from 2015 with the headline "Blackburn man made 15,000 'dirty' calls in 91 days to total strangers", reporting that the same man had been convicted for causing a public nuisance.
A Lancashire Constabulary officer was even quoted as saying: "the scale of it was quite breathtaking", suggesting that the force should have been aware of Khan's past when they investigated him in 2023.
"I'm dismayed that it was such a monumental effort and wonder how many other men committing crimes go unpunished because of the inefficiency, the failures and the delays," said Ms Manning
"Getting justice shouldn't be this hard and getting justice shouldn't be the victim's struggle."
Data for England and Wales show that police are increasingly focusing on so-called non-crime hate incidents - while burglaries and shoplifting go unpunished. Tens of thousands of NCHI have been recorded since 2014.
The Met Police admitted their handling of the case "clearly fell short".
Lancashire Police said their initial handling "did not meet the standard expected".