Prison chiefs have launched an urgent probe into how a murderer was able to use social media from his jail cell while on trial for killing an Ipswich teenager.

East Anglian Daily Times: Isaac Calver was one of four men found guilty of murdering Tavis Spencer-Aitkens last week Picture: INSTAGRAMIsaac Calver was one of four men found guilty of murdering Tavis Spencer-Aitkens last week Picture: INSTAGRAM (Image: Instagram)

The prison service hastily ordered the removal of Isaac Calver’s Instagram account after authorities were alerted to the posts by our reporter.

Calver was convicted of murdering Tavis Spencer-Aitkens last Friday, following an almost four-month trial at Ipswich Crown Court.

MORE: Teenager killer cries in the dock as guilty verdict is read outThe 19-year-old was on remand at HM Prison Chelmsford while he and five others stood trial for the killing in Packard Avenue last June 2.

Calver, of Firmin Close, Ipswich, was among three defendants to regularly appear in music videos, made by members of the JBlock gang under the name YTBYTN.

Calver posted two photographs from his jail cell, while on remand, under the Instagram username ‘flex_ytb’.

One of the images was posted with the description “me and my ones” and shows Calver holding what appears to be a hand-rolled cigarette.

Another post had gained more than 300 ‘likes’ between being posted and Calver being convicted of murder last week.

A Prison Service spokesman said: “This behaviour is unacceptable.

“We have had the account removed and are investigating as a matter of urgency.”

He continued: “We are investing £2 million across the prison estate to find and block mobiles, and prisoners found using a mobile can face extra time behind bars.

“We are also taking robust action to tackle gangs operating in prisons, and earlier this week announced a £30m investment in new security measures to disrupt this activity.”

Known as ‘Flex’, Calver recorded ‘trap’ music with accomplices Aristote Yenge, 23, also known as ‘Gio’, and Kyreis Davies, 17, who went by the name ‘Youngz’.

All three were convicted of murdering Tavis Spencer-Aitkens, along with Adebayo Amusa, 20, who was known to peers as ‘Snipes’.

Callum Plaats, 23, who was cleared of murder but found guilty of manslaughter, was known as ‘Chico’, but did not appear in YTBYTN videos, nor did Leon Glasgow, 42, who was cleared of murder and manslaughter.