The household of jailed British-Egyptian pro-democracy activistic Alaa Abdel Fattah person demanded authorities successful Cairo supply impervious helium is inactive alive.
They person not heard from him since helium escalated his seven-month hunger onslaught connected Sunday by refusing water.
His sister told the BBC that it felt arsenic if they were "dealing with a implicit achromatic hole", with the UK authorities besides incapable to supply immoderate information.
The Foreign Office has said that Abdel Fattah's detention "must end".
"We proceed to telephone for his urgent merchandise astatine each levels," a spokesperson told the BBC connected Tuesday night.
Prime Minister Rishi Sunak raised his lawsuit with Egyptian President Abdul Fattah al-Sisi astatine the COP27 clime acme successful Sharm el-Sheikh connected Monday and "made wide the UK's anticipation that the lawsuit is resolved swiftly", they added.
UN quality rights main Volker Türk and German Chancellor Olaf Scholz besides urged Egypt to instantly merchandise Abdel Fattah connected Tuesday.
"Abdel Fattah is successful large danger. His adust hunger onslaught puts his beingness astatine acute risk," Mr Türk warned, describing him arsenic 1 of a fig of radical successful Egypt who had been "arbitrarily deprived of their liberty and incarcerated aft unfair trials connected aggregate occasions".
Egypt's ngo to the UN successful Geneva rejected the statement, informing that it "deliberately undermines the independency of the judiciary and the regularisation of law".
"The characterisation of a judicial determination arsenic 'unfair' is an unacceptable insult," it said, adding that Mr Turk seemed to person "relied connected unsubstantiated accusation derived from sources propagating mendacious allegations".
French President Emmanuel Macron said connected Monday that helium had been assured by Mr Sisi that Egypt was "committed to ensuring that [the] wellness of Alaa Abdel Fattah is preserved".
But Abdel Fattah's household expressed interest that specified comments mightiness mean situation authorities were force-feeding him oregon putting him connected intravenous drips against his will.
Abdel Fattah, a 40-year-old begetter of one, archetypal roseate to prominence during the 2011 uprising that forced long-time President Hosni Mubarak to resign.
Since Mr Sisi came to powerfulness successful 2014 aft starring the military's overthrow of Mubarak's democratically elected successor, helium has spent astir of the clip successful situation oregon constabulary detention.
Last year, helium was convicted of "spreading mendacious news" successful a Facebook station - a complaint quality rights groups condemned arsenic spurious - and sentenced to 5 years successful prison.
He began a partial hunger onslaught successful April, hoping to unit Egypt into astatine slightest allowing British diplomats to sojourn him.
With authorities continuing to garbage consular access, Abdel Fattah told his household successful a missive from Wadi al-Natroun situation connected 31 October that helium would portion lone h2o until the commencement of COP27 of Sunday, and would past halt adjacent doing that.
"The Egyptian authorities are not providing immoderate information. UK officials successful Egypt are incapable - to our cognition - to get immoderate factual accusation astir Alaa's wellbeing and however helium is doing," his sister, Mona Seif, told the BBC's Breakfast programme from London connected Wednesday morning.
"My parent is, close now, heading to the situation for the 3rd time successful a row, waiting for a missive oregon thing to beryllium that helium is live and adjacent that helium is inactive there. We person nary thought if helium has been transferred to different determination and that we haven't been told."
Ms Seif said situation officials were claiming that Abdel Fattah had refused to constitute a letter.
"We person nary mode of verifying [that]. So we don't cognize if helium is being prevented from penning the missive oregon helium has deteriorated beyond the constituent wherever helium can't adjacent beryllium cognitively contiguous to constitute america a letter. Or if helium is really refusing to constitute the missive and thing has triggered that effect from him."
She explained that her member "cannot endure immoderate much clip successful jail" and that helium had decided to escalate his hunger onslaught during COP27 due to the fact that the satellite was focusing connected Egypt.
"We and helium genuinely judge that if helium doesn't get retired of situation portion COP27 is happening, Alaa is ne'er going to marque it retired of prison.
"The Egyptian regime... intends for him to enactment successful situation until helium dies. And this is simply a punishment wholly for him being outspoken astir their crimes and quality rights violations."
Ms Seif besides lamented that the British authorities had truthful acold not shared with the household immoderate program oregon timeline for Abdel Fattah's release.
"What they tin bash is bring Alaa location connected a plane. This is not unheard of. It has been done for dual nationals with US citizenship, Canadian citizenship, with French citizenship. So I'm not definite wherefore the UK authorities is failing to bash truthful erstwhile Alaa is successful a captious condition."
David Lammy, the shadiness overseas caput and the Labour constituency MP for Mona Seif and her sister Sanaa, told the BBC's Today programme that the Foreign Office should person acted sooner and utilized leverage that the UK had implicit Egypt.
"We person a £4bn trading concern with Egypt. That is tremendous influence. Why has it taken months and months and months for the Foreign Office to act? The premier curate has efficaciously been dragged into this lawsuit due to the fact that of COP. That should not person been the case."
"I've got to archer you that UK citizens person been badly, severely fto down."