A man who beheaded his boss and planted his head on an industrial gas factory fence in France was found dead in his prison cell, jail officials said Wednesday. Yassin Salhi, who was previously under surveillance for radicalization and connections to a Salafist movement, hanged himself from the bars of his cell with bedsheets late Tuesday, prison authorities at Fleury-Merogis prison, in the southern suburbs of Paris, said, according to Agence France-Presse (AFP).

Salhi who worked as a driver and deliveryman at the factory was charged late June with murder of his boss Herve Cornara. Salhi also took a selfie with Cornara's decapitated head, surrounded by Islamic flags, and sent it to one of his friends in North America via WhatsApp. The 35-year-old also attempted to blast his workplace but was arrested. He was charged with attempted murder linked to terrorism the same month.

Jail authorities termed Salhi’s death as suicide. Salhi was reportedly placed in solitary confinement but was not considered a suicide risk. He had maintained that there were no religious connections to his crime, but prosecutors were pressing charges of Islamic-related terrorism against him.

Salhi had previously been investigated in 2006 and for links to the Salafist movement, French Interior Minister Bernard Cazeneuve said in June, according to the Telegraph

Salhi was under surveillance for a few years after 2006. He came to the intelligence’s notice in 2013 because of his alleged links to radical Islam. At the time he reportedly donned a beard and a traditional North African robe called a djellaba.

"He was investigated in 2006 for radicalization, but [the investigation] was not renewed in 2008. He had no criminal record," Cazeneuve reportedly said.