Instagram has passed thousands of pages of “pretty dreadful” material from the account of Molly Russell to her family’s legal team, a court heard.
The 14-year-old killed herself in 2017 after viewing graphic images of self harm and suicide on the platform.
A pre-inquest hearing on Friday was told not all the material had been studied yet as it was too difficult for lawyers and police to look at for long.
A date for the inquest itself is yet to be set.
The inquest will look at how algorithms used by social media giants to keep users on the platform may have contributed to her death.
Oliver Sanders QC told Barnet’s Coroner’s Court how Instagram’s parent company Facebook had recently released a “significant volume” of material relating to the case.
He said: “We haven’t been able to review it all yet. Some of it is pretty dreadful and it is not something that can be reviewed in a long sitting and certainly not late at night.”
He added certain parts of the material had been redacted and lawyers and police were trying to find out why.
The court also heard the investigation was seeking the cooperation of Snapchat, WhatsApp, Pinterest, Facebook and Twitter, although until recently only Pinterest had co-operated fully.
But Snapchat could not disclose data without an order from a US court, WhatsApp had deleted Molly’s account and Twitter was reluctant to handover material due to European data protection laws, the hearing was told.
Coroner Andrew Walker said “some or all” of those social media companies could be named as interested parties in the inquest as they would be “best placed” to give technical information for the case.
He also asked for a psychologist with expertise in the potential psychological impacts of viewing extreme material to be appointed to give evidence.
A further pre-inquest review is due to take place on 26 November.