The health of an Irish citizen who went on hunger strike at an Egyptian prison two months ago has sharply deteriorated, his family has warned, urging authorities for his release.

Ibrahim Halawa, 21, was arrested three and a half years ago over his alleged role in violence during protests in Egypt's capital, Cairo - charges which he denies.

He refused glucose for one week at Tora prison hospital and as punishment has been put in solitary confinement, his sister Somaia Halawa told Al Jazeera on Wednesday.

His blood sugar level has dropped to 39 mg/dl, she said. An adult's normal blood sugar level ranges from 70 to 99 mg/dl.

"It's very hard to think about this, but the reality is: How many more days can Ibrahim handle with his health in this state of deterioration?" Somaia said.

Egypt denied that Halawa's health had deteriorated.

In a statement sent to Al Jazeera, the Egyptian embassy in Dublin said: "At this most recent check up he has so far been found to be in good health with no diseases or life threatening condition ... It is untrue that Mr Ibrahim Halawa is on hunger strike and we see no cause for him to fear for his life."

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Halawa was detained in August 2013, when he was 17, along with hundreds of others after taking refuge in a mosque from a bloody crackdown on demonstrators who had protested against the removal of democratically elected President Mohamed Morsi, leader of the Muslim Brotherhood.

Egyptian authorities have repeatedly delayed a mass trial of hundreds, including Halawa, often because one or more defendants were unable to attend. His next trial is due to take place on March 22.

If convicted, Halawa could face the death penalty under Egyptian law.

"Time is of the essence to save Ibrahim's life," Halawa's family said in a statement on Wednesday.

"We ask our [Irish] government to urge the Egyptian government to release Ibrahim on humanitarian grounds."

At the last weekly visit by an aunt on Tuesday, Halawa was in a wheelchair, the family said.

"If something was to happen to Ibrahim physically or mentally" they would hold both the Irish and Egyptian governments responsible, the statement added.

Halawa has gone on hunger strike protests several times throughout his detention and has lost at least 30kg, according to his family.

His lawyers and human rights groups have claimed that Halawa has been beaten, tortured and electrocuted in jail.

'Time for tea and sympathy is over'

Egypt has led an extensive crackdown on the now outlawed Muslim Brotherhood group and liberal activists since 2013, when the military deposed Morsi.

US-based rights group Human Rights Watch says Sisi's government has arrested, charged, indicted or sentenced after unfair trials tens of thousands of people.

According to the Daily News Egypt, Foreign Minister Sameh Shoukry, who is currently in Washington DC, told the United Nations Human Rights Council that Egypt is committed to human rights.

"While Shoukry is in Washington and trying to convince that the situation regarding human rights and the rule of law is fine in Egypt, an Irishman is slowly dying in a prison hospital," Lynn Boylan, a member of the European Parliament representing Sinn Fein, told Al Jazeera.

Irish-#Egypt|ian Ibrahim Halawa, in pretrial detention 1287 days w trial adj 19 times, moved to prison hospital https://t.co/VfXdrUGslA pic.twitter.com/Ej09WYUEjl — Mai El-Sadany (@maitelsadany) February 24, 2017

Boylan, who visited Halawa in 2015, said that news of his deteriorating health was "deeply upsetting".

"The time for tea and sympathy from the Irish government is over," she said.

"They need to make direct contact with President [Abdel Fattah el-] Sisi and leave him in no doubt that there will be no normalisation of relationships ... as long as an Irish citizen is being treated with such contempt by the Egyptian authorities," she said.

"Until there is a political cost internationally to President Sisi, he will not expend political capital by releasing Ibrahim."

READ MORE: A letter to my brother in Egyptian prison

On February 23, Paul Murphy, a politician in the Irish parliament's lower house, tweeted that Halawa was moved to a hospital in the prison with a heart condition.

Murphy was among a delegation that visited Halawa in January. He said that Egyptian authorities had denied that Halawa suffered from a heart condition during that visit.

Follow Anealla Safdar on Twitter: @anealla