Teenager Molly Russell engaged with tens of thousands of social media posts in the six months before she died, including content which “raised concerns”, a coroner has heard.

The 14-year-old, from Harrow in north-west London, viewed material linked to anxiety, depression, self-harm and suicide before ending her life in November 2017.

Her inquest will look at how algorithms used by social media giants to keep users hooked may have contributed to her death.

A pre-inquest review last September heard how a huge volume of “pretty dreadful” Instagram posts had been disclosed to the investigation by its parent company Facebook.

But a follow-up review at Barnet Coroner’s Court on Monday heard how Facebook remained unwilling to discuss certain aspects of the material disclosed to lawyers representing Molly’s family.

The investigation was also seeking an appropriate expert to comment on the material.

Every day the inquest is delayed presents a potential risk to others exposed to this material

Expressing the need for progress with the investigation generally during the short pre-inquest review on Monday afternoon, coroner Andrew Walker said: “What does trouble me is this matter does need to move on.

“Every day the inquest is delayed presents a potential risk to others exposed to this material.”

Oliver Sanders QC, representing Molly’s family, told the hearing there were two issues with the information provided by Facebook – accessing the data provided in “enormous” spreadsheets which included links to either private or deactivated profiles, and redacted content provided by the company.

He said: “In broad terms, Facebook/Instagram have been willing to discuss the first of those issues, but they are not willing to discuss what other data they might have.”

He said Twitter had provided Molly’s father, Ian Russell, with access to her Twitter profile so he could pore over some of the material she liked or shared.

Mr Sanders said: “In the last six months of her life, she tweeted or retweeted 460 times. Some of those messages raise concerns.”

He said she had liked 4,100 tweets, was following 116 accounts and had 42 followers.

She was a much more active user of Pinterest, with more than 15,000 engagements, including 3,000 saves, in the last six months of her life.

Molly did not have a Facebook profile, the inquest heard.

But in the last six months of her life, she was engaging with Instagram posts around 130 times a day on average.

This included 3,500 shares during that time frame, as well as 11,000 likes and 5,000 saves.

The family’s lawyers have not been provided with the content, just links, some of which do not work or have been deactivated, Mr Sanders said.

The inquest heard the family are looking to identify and instruct a child psychiatrist who will be able to understand the kind of material Molly was accessing in the lead-up to her death, and the effect it may have had on her.

The hearing was adjourned until a date yet to be determined.

Since his daughter’s death, Mr Russell has been a vocal campaigner for reform of social media platforms and set up the Molly Rose Foundation in her memory.

In a statement following the hearing, Tara Hopkins, head of public policy at Instagram, said: “Our intention has always been to be as helpful as possible in this important investigation.

“Some links lead to content that is no longer available because it has since been deleted or belongs to a private account.

“We had to take into account the privacy rights of other Instagram users, which is why certain account names or handles have been redacted.

“We have offered to address all follow-up questions from the coroner and the family in a way that meets our obligations to our users and are committed to doing that.”

Merry Varney, from Leigh Day solicitors, who represent Molly’s family, said: “Our client welcomes the coroner’s recognition that Molly’s inquest should if possible be heard as soon as reasonably possible, and in particular his recognition of the potential harm being caused to other children being currently exposed to similar depressing and graphic material that Molly was.”