The President of the United Arab Emirates is in a stable condition after suffering a stroke, according to the state news agency.
David Cameron has told Daybreak there needs to be a "proper independent investigation" into the alleged police torture of three British men who were on holiday in Dubai.
The Prime Minister said he would raise the need for an inquiry with the visiting president of the United Arab Emirates later today, describing it as the "first step of working out what needs to happen next" in the case.
Mr Cameron played down any possible fallout from the demand, adding: "Look, we have a very good relationship with the UAE and I'm delighted they're here on this state visit this week."
Davena Kumar, the sister of Suneet Jeerh who was sentenced to four years in a Dubai prison for drug offences told Daybreak that the whole ordeal has aged her brother.
She said: "It's a little bit sad to see him like that because he looks very aged, he's all greyed, the side of his hair, his beard and his eyebrows have all greyed, he looks quite distraught."
Alex Williams, the brother of Karl Williams told Daybreak that "all charges should be dropped" against his brother who was sentenced to four years in a Dubai jail yesterday for drug offences.
He said: "Four years is definitely better than the death penalty that they were originally facing, but like I said because of the way they were treated, all charges should be dropped, they shouldn't be allowed to be tortured, and as British citizens I think that's unacceptable."
David Cameron is expected to raise the cases of three Britons who were allegedly tortured in Dubai when he meets the president of the United Arab Emirates later today.
The state visit by Sheikh Khalifa bin Zayed Al Nahyan comes amid allegations that Grant Cameron and Suneet Jeerh, both 25, and Karl Williams, 26, were abused by police.
Mr Cameron expressed his concern at the torture allegations in a letter to the charity Reprieve and said he intended to raise the subject with the president. His spokesman later said that there will be "no no-go areas" in their discussions.
The Sheikh will visit Downing Street for talks with the Prime Minister before laying a wreath at Westminster Abbey.
Britain's close links with the United Arab Emirates (UAE) were praised by the Queen as she welcomed the nation's president to the UK.
Sheikh Khalifa bin Zayed Al Nahyan, on a two-day state visit to the UK, was formally greeted by the Queen and Duke of Edinburgh during a ceremony full of pomp and military splendour staged at Windsor Castle.
The Queen later hosted a state lunch for the Arab leader and his ministers and officials, with British guests led by Prime Minister David Cameron.