- Ahmed Aweys from east London was sentenced to 25 months in jail last year
- He disseminated terrorist material along with his sister Asma who was also jailed
- Aweys was released on licence in August but used unauthorised bank account
- He also had a second phone not declared to police he used for texts and selfies
- Judge gave him 16 months for each offence to run concurrently with each other
Ahmed Aweys, 34, from Chadwell Heath, east London, was sentenced to 25 months in jail last January for three charges of disseminating a terrorist publication.
He was arrested along with his sister Asma after sharing sickening ISIS videos in their family Whatsapp group.
They made jokes about the Manchester and Westminster terror attacks and downloaded copies of the jihadi magazine 'Rumayah' with advice about how to make napalm and Molotov cocktails and the 'perfect knife' for killing.
In one chat, Ahmed said: 'The biggest advantage that we have is we are embedded in their societies, we are the enemy within and they know not.'
He was made subject of a terrorism notification order as part of the terms of his release on licence in August.
But in September, police found he had used an unauthorised bank account belonging to his sister to receive three Department for Work and Pensions payments after applying for universal credit.
When police went to arrest him, they found he also had a second phone he had not declared to police, the Old Bailey heard.
An examination of the mobile device revealed he had used it to send texts, make calls, search the internet and had even taken a selfie on it.
Aweys, who was recalled to prison, pleaded guilty to two charges of breaching notification order requirements and appeared to be sentenced at the Old Bailey by video link from Wandsworth jail.
Mr Justice Sweeney handed him 16 months for each offence to run concurrently with each other and his original sentence.
The judge said the defendant had deliberately flouted the terrorism notification requirement.
He said: 'The requirements are clearly there for the important purpose of enabling the authorities to keep track of the activities of those who have been convicted of terrorism offences and thereby minimise the danger by them to members of the public.'
The purpose of the jail sentence was 'punishment, deterrent and protection of the public', he said.
The court heard Aweys was due for release in September.
Upon his previous conviction, the court heard how his sister Asma said about the Westminster incident in 2017, which left four dead: 'This was by the decree of Allah.'
Messages discussing the terror attack at the Manchester Arena were also found on her phone, including one which read: 'It was the shaytaan [Arabic word for devil] Ariana Grande's concert.'
The family's extremist views were revealed after a tip off that Ahmed Aweys and his two half-brothers were planning to break into a Muslim-run jewellery shop in Ilford Lane, east London.
They were caught red-handed and during searches of their homes police also found £60,000 in cash and £10,000 in gold.
Messages found on their phones showed Ahmed Aweys discussing fraud with his brother-in-law Abdulaziz Abu Munye, a former street robber, and telling him he was entitled to take from the 'kuffr' [infidels].
As part of Operation Be Pretty 2, police discovered that the family, who are of Somali origin, were sharing ISIS propaganda and messages of support in a family Whatsapp group.
Ahmed Aweys pleaded guilty to using WhatsApp to distribute the ISIS online magazine Dabiq and the video Flames of War 2 to Mohammed Abu, his half-brother who was involved in the robbery plot.
Flames of War 2 is a film released by the media wing of ISIS in 2017 in both Arabic and English.
'It shows brutal executions of various kinds, battle footage, references to attacks in the West and praising the faith-based nature of the participants,' Lee Ingham, prosecuting, said.
'There are computer generated scenes of rockets heading towards the US.'