The family of a young mother who went missing four years ago has this week described the anguish her disappearance has caused to her 10-year-old daughter – and appealed to anyone with information to help find her mum.

Lana Purcell, who was last seen in January 2011 when she was 26, was a former pupil of Parliament Hill School in Highgate Road and was well known in the Queen’s Crescent area.

Her sudden disappearance, described as “out of character” by police and family, has baffled detectives for four years and left her loved ones desperate for answers.

Davina Purcell, sister of Lana, said it was now having a traumatic effect on Lana’s daughter.

She said: “It was Lana’s daughter’s birthday last month, then came Christmas, and next month is Lana’s birthday itself.

“These are the times she thinks her mum is going to come back to see her. But each time I have to explain she might not turn up.

“She’s upset and it’s very sad. But how do you explain something like this to such a young child?”

Theories on Lana’s disappearance vary but include claims she was taken after becoming mixed up in a criminal world and stealing from drugs lords in Camden. This was said by police to be “one line of inquiry”.

With police criticised for “dragging their feet” in the search, some residents have led their own.

This includes one man who, in March last year, handed the Ham&High a notebook purporting to contain the names of drug kingpins ultimately responsible.

In the same month, the police gave their biggest indication yet that something criminal had occurred to Lana when they revealed that Homocide and Serious Crime Command detectives were to lead the search.

Their investigation has included numerous searches, interviewing large numbers of people, and viewing hours of CCTV, but it is thought a conspiracy of silence is frustrating progress.

DCI Tim Duffield, said: “We need to speak to anyone who knew Lana, knew her friends and associates or who has any information that can help us find her. Lana was devoted to her child and it is extremely out of character for her not to be in touch. Allegiances shift over time and I would like to hear from anybody who now feels that they can speak out. If you have any information you can speak to us in complete confidence.”

If you have any information, contact the investigation team on 020 8358 0400, or Crimestoppers anonymously on 0800 555 111.