Kirsten Heaven, who represents Cpl Ellement's two sisters, told the inquest: "The family are devastated and upset this disclosure has come so late in the day."
Adjourning proceedings until Monday morning, the coroner said there was a "danger" in pursuing information which was "unrealistic to find" and which may be of little relevance to the inquest.
"I suggest all urgency is given to track down any missing documents," Mr Rheinberg said.
"I'm going to grant the application (for adjournment) on strict and immediate terms."
A coroner's ruling into the death in Wiltshire of Anne-Marie Ellement, a soldier who said she had been raped and bullied, has been unexpectedly delayed today.
It comes after lawyers for the military revealed they had uncovered new documents, including a reference to a diary and mobile phones Corporal Ellement's family say were never passed to them.
Lawyers for the family of Royal Military policewoman, who was found hanging at her barracks in Bulford in October 2011, have accused the military police of a gross breach of guidelines on evidence disclosure.
Detective Inspector Iwan Jones told a pre-inquest review hearing in Aberdare Coroner's Court the scale of investigation had widened:
Police investigating the deaths of three soldiers, including one from Bath, who died during an SAS selection programme in the Brecon Beacons say they have not yet interviewed everyone they would like to.
Army reservists Edward John Maher, 31, Craig John Roberts, 24, and 31-year-old James Dunsby (from Bath) died while taking part in a gruelling SAS selection exercise on one of the hottest days of the year. A number of other soldiers also collapsed and needed medical attention.
It is thought the group were carrying out an exercise known as the "Fan Dance", which involves marching up 886-metre high Pen Y Fan mountain and down the other side carrying a weighted pack and rifle, then doing the route in reverse, in a set time.
A hearing is due to be held into the death of a TA soldier from Bath who died on one of the hottest days of the year.
Corporal James Dunsby died in July with two other reservists on a training course in the Brecon Beacons.
They were all carrying heavy packs.
Temperatures hit 30 C.
The pre-inquest hearing will look at progress on the army and police investigations.
The funeral of a reservist soldier from Bath will be held in Wiltshire on Thursday.
31 year old Corporal James Dunsby died from injuries he suffered during SAS selection training in extreme heat in July.
An inquest heard, the MoD analyst suffered multiple organ failure.
The service will take place in St James Church in Trowbridge.
An inquest has heard how a soldier from Bath, who died following an SAS training exercise, suffered multiple organ failure.
Corporal James Dunsby, was pronounced dead in hospital 17 days after collapsing in the Brecon Beacons on South Wales's highest mountain, Pen Y Fan, on one of the hottest days of the year. Fellow reservists Edward John Maher and Craig John Roberts also died in the incident.
A tribute page has been set up in honour of Corporal James Dunsby.
The 31 year old worked in Bath for the MoD as an analyst.
Cpl Dunsby died on Tuesday in hospital from injuries he suffered during SAS selection training in extreme heat a fortnight ago.
A part-time soldier based in Bath has been named as the third man to die after a training exercise in the Brecon Beacons.
Corporal James Dunsby, who was 31-years-old, died yesterday in hospital from injuries he suffered during SAS selection training in extreme heat a fortnight ago.
He worked in Bath for the MoD as an analyst.
Laura Makin-Isherwood reports: