York University chef Claudia Lawrence (pictured) was 35 when she disappeared in March 2009

Every year for the past decade, the same three Christmas cards have decorated Joan Lawrence’s mantelpiece. All are signed ‘Love Clauds’ in her daughter’s neat, careful handwriting.

As she takes them out of storage and lines them up, Joan likes to imagine Claudia is still living happily a few miles down the road, her cheerful voice only a phone call away.

Her favourite card shows a golden retriever puppy. Claudia loves animals, she says.

Although Claudia has been missing for ten years and the police presume she has been murdered, 76-year-old Joan likes to talk about her daughter in the present tense.

She clings to the tiny sliver of hope that Claudia is alive somewhere and, one day, a new card from her will drop on the doormat.

‘As her mum, I feel no cut-off. I can’t believe she is dead,’ she says. ‘I am never, ever giving up hope. Someone knows the truth and I just wish they’d end this torture by telling me.’

Claudia Lawrence, a York University chef, was 35 when she disappeared in March 2009 from her two-bedroom terrace home on the outskirts of the city, where she lived alone.

Although Claudia (centre) has been missing for ten years and the police presume she has been murdered, 76-year-old Joan likes to talk about her daughter in the present tense

Joan’s last Christmas present to her daughter, a short coat which Claudia loved, still hangs in the wardrobe, barely worn. The house lies empty, waiting for her return.

One of Claudia’s last phone calls before she vanished was from her mum. It was about 8.30pm and Claudia planned to go to bed early because she had a 6am shift the next day.

Her old Vauxhall Corsa had broken down and it was a 45-minute walk to work at Goodricke College, on the York University campus, so she needed to leave the house by 5.15am.

‘She didn’t like walking on her own in the cold and dark, but every time I offered her money for a taxi she refused,’ says Joan.

They talked of meeting up for Mother’s Day and chatted about the TV programme Location, Location, Location.

Claudia's mother Joan Lawrence said she is 'never, ever giving up hope' and 'can’t believe she is dead'

At 9.12pm, Claudia received a text message from a friend living in Cyprus, but she did not reply. It is not known if she even read it.

Since then, there has been no trace, no word, no clue as to what has happened to Claudia, whose pretty face still smiles, frozen in time, from missing posters.

The case remains one of Britain’s most perplexing unsolved mysteries.

Despite an extensive suspected murder investigation and a cold case review costing a reported £1.5 million, no one can explain how Claudia simply vanished or tell Joan where she is.

North Yorkshire police took 2,517 statements, checked 1,771 vehicles, searched 38 homes and business premises, examined 64 scenes and tested more than 200 items for DNA, all of which yielded no concrete evidence.

Detectives originally feared Claudia had been abducted by a stranger as she walked from her home in Heworth to work, failing to arrive for her early shift on Thursday, March 19, 2009.

There was no evidence of a break-in at her home, nor any sign of disturbance. Her bed was made, dirty plates were stacked in the sink and her slippers had been left neatly in the hall.

Her father Peter, a retired solictor, had reported her missing on the Friday after one of his daughter’s female friends alerted him when Claudia didn’t turn up to meet her in the pub, as they’d agreed, on Thursday night, and phone calls the next morning went straight to voicemail.

Every year for the past decade, the same three Christmas cards have decorated Joan Lawrence’s mantelpiece. All are signed ‘Love Clauds’ in her daughter’s neat, careful handwriting

Checking her home, he found that Claudia had left behind her passport, bank cards and jewellery, apparently taking just her chef’s whites in a small Karrimor rucksack, which has never been recovered.

Following a TV missing person appeal, one witness came forward to say they had seen a woman matching Claudia’s description talking to a left-handed smoker in the street. Another told police they had seen a couple arguing near the campus.

Then, to the Lawrence family’s distress, the investigation suddenly altered course. Leading the suspected murder inquiry, Det Supt Ray Galloway — since retired — described Claudia’s love life as ‘complex and mysterious’ during an appeal on BBC TV’s Crimewatch.

Early police inquiries revealed that Claudia, like many attractive single women, had dated a number of men: around 12 over a five-year period. At least one of them was married.

Attention focused on Claudia’s busy social life, which centred largely on the Nag’s Head pub, a few doors down from her home, where police met with ‘a wall of silence’.

Friends of Claudia Lawrence (left to right) Hazel Dales, Martin Dales, and Suzy Cooper, light candles at York Minster on the tenth anniversary of her disappearance, on March 18 this year

To date, nine people have been arrested or interviewed under caution, and files were submitted to the Crown Prosecution Service in relation to several individuals, but there was insufficient evidence to bring charges.

On the tenth anniversary of her disappearance, Det Supt Dai Malyn, now leading the inquiry, said: ‘It remains the case that we strongly suspect key evidence is being withheld that could provide the breakthrough we all want to see, not least Claudia’s heartbroken family.’

North Yorkshire police still believe Claudia’s disappearance is linked to her private life and to someone she knew and may have let into her home on the night of Wednesday, March 18.

Claudia’s mobile phone never left the local area and was deliberately switched off some hours after she failed to turn up for work.

Miss Lawrence's father Peter at a press conference in York with Detective Superintendent Ray Galloway (right) in April 2009 when he said police were now treating it as a murder inquiry

In a recent Channel 5 documentary called Missing Or Murdered, one of Claudia’s work colleagues — speaking for the first time — suggested that shortly before her disappearance she had hinted at a new lover whom no one yet knew about.

But what about the other theories put forward over the years?

Could Claudia have fallen victim to double murderer Christopher Halliwell as she walked to work? Halliwell, a taxi driver who is serving a full life sentence for the sexually motivated murders of Becky Godden and Sian O’Callagan in Wiltshire, had a relative in Yorkshire.

Joan, who has become close to Becky’s mother, Karen Edwards, thinks the theory ‘credible’.

One of Claudia’s last phone calls before she vanished was from her mum. They talked of meeting up for Mother’s Day and chatted about the TV programme Location, Location, Location. Pictured: Claudia aged 10

Alternatively, could Claudia have fled to Cyprus, smuggled overseas in a van, to start a secret new life for reasons unknown?

The last text she received was from a male friend living in Paphos. She had visited the country two years earlier with a girlfriend, and had been offered kitchen jobs. She had also spoken about wanting to work with horses in Cyprus.

Police sent officers to investigate, but could find no evidence to support the theory. And would Claudia have chosen to disappear just four days before she and Joan were due to meet up for Mother’s Day?

Claudia’s father, Peter, told the programme: ‘She wasn’t a mastermind who would have been able to devise a way of going abroad without using a passport or bank account.’

Although she and Peter have been estranged for more than 20 years, Joan can’t help but agree.

Which leaves the final theory: that Claudia may have been sex-trafficked to Amsterdam and has been held against her will ever since.

Mrs Lawrence revealed on the programme that she had received information from a potential witness — originally from York — who claimed to have recognised Claudia at Hartlepool Marina, from which boats travel to Holland.

Joan added that she’d heard about ‘some kind of white slave trade going on’. In July 2012, a private detective had also reported seeing Claudia in Amsterdam. However, when Dutch police investigated the lead, they found no trace of her.

Today, Joan admits she knows no more about what really happened to Claudia than she did ten years ago. She calls the early police investigation ‘one disaster after another’.

Joan's favourite Christmas card shows a golden retriever puppy. Claudia loves animals, she says

She will never understand why North Yorkshire police initially used an old photograph of Claudia with blonde hair in their missing person appeal, when she had changed the colour to brunette.

‘I offered them a more up-to-date photograph, but it wasn’t changed for four years, until Dai Malyn took over,’ she says.

Joan is now pinning her hopes on the new cold case team investigating the crimes of Halliwell, which is casting fresh eyes over her daughter’s disappearance.

She has faith in them — but ever since that early Crimewatch appeal, she says, she has been trying to correct the false impression it left that her daughter was some kind of ‘home-wrecker’ or good-time girl.

She believes the appeal served only to drain sympathy for Claudia and alienate potential witnesses.

Police search a nature reserve in York for Claudia after she went missing in March 2009

‘Why is it always the woman who is judged?’ asks Joan, who insists that Claudia’s love life was no different from that of many other single women.

‘You could ask, why are these so-called married men looking for a girl like my daughter? They’re not so innocent, nor do they always let on that they’re married. Everyone who knew Claudia — all her real friends in Malton — didn’t recognise her from how she’d been portrayed.’

Privately educated, Claudia grew up with her parents and older sister Ali in the pretty market town of Malton, also in North Yorkshire, where Joan still lives.

Her father was a solicitor and before her parents split up in 1996, it was a comfortable upbringing. Claudia played the flute, and on Saturdays the girls would have riding lessons. Claudia’s world revolved around her ponies, Brandy and Cobweb.

Joan thought Claudia would make a wonderful veterinary nurse, but after school she decided to go to catering college and loved it, eventually landing a job as a chef at the University of York.

Mother and daughter, both vegetarian, were very close and tried to meet up weekly, either for lunch or to go shopping. They spoke on the phone every day.

Police officers enter a terraced property in York as part of the investigation in August 2009

Claudia was in the habit of calling her mum for a chat on the walk home from work, and she was last seen alive when CCTV cameras picked her up posting a letter at a postbox not far from her home.

Claudia had been single for about 18 months after a long on-off relationship ended, but Joan says she was quite happy on her own.

‘She lacked self-confidence from a young age and never thought she was pretty,’ she says. ‘When we walked down the street together, men would always look at her, but she never even noticed.

‘She never seemed bothered about getting married or having children, though she loved her two nephews. She told me she was quite happy being single.

Police outside the Nags Head pub in York, which they searched for a second time in June 2009

‘Claudia loved her job. She liked cooking for people, especially children in the creche. Working unsocial hours, it was quite difficult having a relationship, but she was content with her lot.

‘She was serious about her career, even though it wasn’t very well-paid, and she’d never drink during the week when she had an early shift. She didn’t want to take the risk driving the next morning.

‘Claudia worked in a male-dominated industry, so most of her friends were inevitably going to be men.

‘Yes, she would go and visit them and they were married, but Claudia was friends with their wives, too. I sometimes used to go with her and we’d buy presents for their children. Claudia was a very straightforward person. There was nothing mysterious about it.

‘It seemed to me that, in the beginning, every male Claudia knew was being treated as a potential suspect by police. Who would want to risk coming forward? But with the new team, it’s different.’

So what does Joan think happened to Claudia?

‘Who’s to say she isn’t living somewhere, perhaps married with children, but unable to contact us for whatever reason?’ she says.

‘I just don’t know. It’s all speculation. But someone knows the truth, and my teenage grandsons, Claudia’s nephews, keep telling me, “Don’t give up, Gran. Keep going.”

‘After ten years it doesn’t get any easier. Every Christmas I long to buy my daughter presents, just like every other mum.

‘But I can’t, can I?’