Cairo - The family of Egypt's jailed dissident Alaa Abdel Fattah, who has been refusing food and water, said Thursday prison authorities had told them he is "under medical intervention".

The family have repeatedly demanded information on the health of the British-Egyptian activist in recent days, amid what they said were "rumours of force-feeding".

His mother Laila Soueif, at the Wadi al-Natroun prison north of Cairo, was informed that "medical intervention was taken" with Abdel Fattah "with the knowledge of judicial entities", his sister Mona Seif wrote on Twitter.

International concern has mounted since Abdel Fattah, 40, escalated his months-long hunger strike by also declining liquids since Sunday, the start of the UN climate summit COP27 hosted by Egypt.

Abdel Fattah, a veteran pro-democracy and rights campaigner, is serving a five-year prison sentence for "spreading false news" by sharing a Facebook post about police brutality.

A key figure of the 2011 uprising that toppled longtime autocrat Hosni Mubarak, Abdel Fattah gained British citizenship this year.

"Surely our mother should see him, or someone from @UKinEgypt (British embassy in Cairo) so we understand his real health status!!" Seif added on Twitter.

The dissident's aunt, novelist Ahdaf Soueif, earlier this week said the family was concerned about "rumours of force-feeding and of sleep-inducing drugs".

British Prime Minister Rishi Sunak, French President Emmanuel Macron and German Chancellor Olaf Scholz have all voiced concern and called for his release.

United Nations rights chief Volker Turk has warned Abdel Fattah's "life is in great danger".

Activists at COP27 have posted widely on Twitter under the hashtag #FreeAlaa, and several speakers have ended with the words "you have not yet been defeated" -- the title of the jailed activist's book.

Human rights groups estimate that some 60,000 political prisoners are held in Egypt, many of them in brutal conditions and overcrowded cells, accusations which Cairo rejects.

© Agence France-Presse