Jihadi Jack admitted he was a terrorist in a Facebook message to his parents while asking them to help him come home, a court heard.
But their lawyers say counter-terrorism police had given the parents from Oxfordshire the ‘green light’ to send money to their radicalised son.
Jurors were told while the chief senior investigating officer, Louise Tompkins was off, the wrong advice was handed down the chain of command.
John Letts, 58, and his wife Sally Lane, 56, (pictured outside court), are on trial at the Old Bailey accused of funding terrorism by sending money to their radicalised son Jack Letts
Specialist Case Investigator Kerry Corbett told the Old Bailey: ‘John was angry that he had been given the incorrect advice.
‘He said that he had sent a message to Jack saying that they had been given the all clear and that they would be sending him money.
‘He was concerned that it might be used against him by the police. They said they did not think the money was being used for a terrorist purpose.
‘That was because it was helping Jack to leave where he was. Sally said that the guidelines state that that they might be investigated but not necessarily prosecuted.
‘She seemed to think it would be unlikely that they would be prosecuted.’
Jack Letts (pictured) was living in the ISIS stronghold of Raqqa in Syria at the time his parents wired him the money
Jurors heard John Letts told the officer: ‘Jack was very angry that day as his friend had been killed in an air strike.’
Alison Morgan, QC, prosecuting, said: ‘Did John show any message where Jack had said that?’
Ms Corbett replied: ‘I don’t believe so’.
In a Facebook exchange Jack told his parents: ‘Don’t tell me now you hate black people as well as us terrorists.’
Ms Corbett said she asked the parents whether the tone and wording of the messages made them re-think their position.
‘I asked them why they believed Jack was telling the truth at this stage about wanting to leave. They replied that he wouldn’t lie.’
Henry Blaxland, QC, who represents the 23-year-old’s father, summarised his client’s position: ‘He was angry because, and he made this clear to you, he felt that the police were putting his son in danger.
‘He genuinely believed he was in mortal danger to use his expression.’
Jurors were told while the chief senior investigating officer, Louise Tompkins was off, the wrong advice was handed down the chain of command
Giving evidence retired Detective Inspector Tony Lees told the court: ‘What I said was it was not an offence to send him money. However, it could be if the purpose of sending that money was for terrorism.
‘So, I pointed out there is potential for committing an offence under the Terrorism Act – that offence being Funding Terrorism section 17 of the Terrorism Act.
‘And, I pointed out for the offence to be committed money would have to be transferred but there must be a reasonable case for them to believe that the money was for the purpose of terrorism.
‘As a result, if they were to send money it is imperative that they keep accurate reasons why they have done so, what their belief was and the transaction.’
Ms Morgan asked Mr Lees if he thought he had given permission for the parents to send money to their son at any stage.
He replied: ‘I didn’t. My understanding was he was fighting for Islamic State.’
The prosecution allege Lane and Letts jointly attempted to send £1,723 to their son between September 2015 and January 2016.
John Letts and Sally Lane, of Chiswell Road, Oxford, deny three charges of entering into a funding arrangement for the purposes of terrorism.
The trial continues.