By Daid Hughes

Russia’s ambassador to the UK has stepped up demands to be allowed to see Sergei Skripal and his daughter Yulia, suggesting the pair may be being detained by the British state.

Alexander Yakovenko said the pair were “isolated”, adding: “You can call it kidnap.”

Mr Skripal, 66, and his daughter, Yulia Skripal, 33, were admitted to Salisbury District Hospital after coming into contact with the military-grade nerve agent novichok.

The pair were left fighting for their lives after being found unconscious on a park bench in Salisbury, Wiltshire, on March 4.

READ MORE: Salisbury incident nerve agent 'delivered in liquid form'

Yesterday morning, it was confirmed that Mr Skripal, a former spy, had left hospital, following his daughter's discharge on April 10.

In a statement, Scotland Yard said: "Detectives from the UK's Counter Terrorism Policing network continue to investigate the attempted murders of Sergei and Yulia Skripal in Salisbury in March this year.

"They are both making good progress and we are pleased that Mr Skripal has now also been released from hospital, which was announced by the NHS earlier this morning."

Mr Yakovenko welcomed the announcement that Mr Skripal had been discharged but claimed the UK is violating international law by not granting access to the Skripals.

READ MORE: Porton Down scientists not able to say Salisbury nerve agent came from Russia

The 1963 Vienna Convention gives consular officials access rights if one of their nationals is in prison, custody or detention.

Mr Yakovenko's comments came as Scotland Yard said it would not discuss "any protective or security arrangements" for Mr Skripal and his daughter following their discharge.

Setting out Moscow’s interpretation of the case, Mr Yakovenko said: “We are saying that they are isolated because we don’t have access to them.

“This is our interpretation.

"You can call it detained, you can call it isolated, you can call it kidnap.

“Unless we see them it is difficult to make a conclusion.”

He acknowledged that the Foreign Office had told him they did not interpret the situation in the same way and added: “I got the impression that we will never see them."

Russia has denied involvement in the incident in Salisbury which left both Mr Skripal and his daughter seriously ill.

Mr Yakovenko said: “If it was really Novichok and they were poisoned by Novichok, the consequences would be very serious.

“My question was how they survived from Novichok.”

READ MORE: MI5 chief says Salisbury nerve agent attack deliberate and targeted

At a press conference at his official residence in London after Mr Skripal was discharged, Mr Yakovenko said “we are happy that he is all right”.

He added: “We are still demanding access to these people. We want to understand how they feel.

“We want them to tell (us) personally what they want. If they don’t want our assistance, that’s fine, but we want to see them physically.”

Mr Yakovenko criticised the Government’s attitude towards Moscow, highlighting Defence Secretary Gavin Williamson’s comment that Russia should “go away and shut up”.