Sergei Skripal, who was poisoned with a nerve agent in Britain, triggering a diplomatic crisis with Russia, has been discharged from hospital, the facility said Friday.
"It is fantastic news that Sergei Skripal is well enough to leave," Salisbury District Hospital's chief executive Cara Charles-Barks said in a statement.
Nursing director Lorna Wilkinson said treating him and two others poisoned by the same nerve agent had been "a huge and unprecedented challenge".
"This is an important stage in his recovery, which will now take place away from the hospital," she said.
Skripal and his daughter Yulia, who was visiting from Moscow, collapsed on March 4 on a bench in Salisbury, the city in southwestern England where the former double agent lives.
Police officer Nick Bailey who came to help them was also taken to hospital. He was discharged several weeks after the attack, while Yulia Skripal was treated in hospital for just over a month.
"Treating people who are so acutely unwell, having been poisoned by nerve agents, requires stabilising them, keeping them alive until their bodies could produce more enzymes to replace those that had been poisoned," the hospital statement said.
The poisoning sparked a diplomatic crisis that saw Russia and the West expelling dozens of diplomats in tit-for-tat moves.
Britain has accused Russia of being behind the poisoning, saying it was caused by a type of nerve agent known as Novichok which was developed in the Soviet Union.
UN experts have confirmed that a high-purity nerve agent was used without specifying whether it was Novichok or saying who might be behind the poisoning.
Following Skripal's release, the Metropolitan Police said it was making "good progress" in the case.
"This is a complex investigation and detectives continue to gather and piece together all the evidence to establish the full facts and circumstances behind this dreadful attack," it said in a statement.
Russia has challenged Britain to provide evidence in the case and has requested consular access to Skripal and his daughter.
The Russian embassy in London accused Britain of blocking access to the pair in defiance of diplomatic convention, airing the claims in a set of sensational social media posts.
The Foreign and Commonwealth Office said their offer of consular assistance had been passed to Yulia Skripal but that she had turned it down.
Both she and her father are now likely to be in protective custody.
"In the interests of Sergei and Yulia's safety, we will not be discussing any protective or security arrangements that are in place," the Metropolitan Police said.
Skripal is a former Russian military intelligence officer who passed information on Russia's agents in Europe to British security services, resulting in imprisonment in his homeland.
He moved to Britain as part of a spy swap in 2010 and has lived there ever since.