Canadian authorities are working with French police to help find the recipient of a photograph purportedly taken by an Islamist suspected of decapitating his boss in France.
Sources close to the investigation into Friday's attack near Lyon say Yassin Salhi, a 35-year-old married father-of-three, sent a picture of himself with the severed head via the WhatsApp messaging service to a Canadian number.
"Though I can't comment on operational aspects of national security, I can say that we are helping French authorities in their investigation," said Jean-Christophe de Le Rue, spokesman for Canadian public safety minister Steven Blaney.
The message was sent to a Canadian number, but investigators said they were still working to determine the final recipient, as the number used could be a relay to another phone in another location.
Authorities are questioning Mr Salhi about the attack, during which he also drove his van into a warehouse packed with dangerous gases in an apparent bid to blow up the factory and himself.
A source close to the investigation said Mr Salhi has admitted killing his boss, 54-year-old Herve Cornara.
Canadian officials did not give details about how they are helping the French, but police powers allow them to trace calls or locate a phone by its number.
"A government's first duty is to ensure the safety of its citizens," the spokesman said.
French police found the head of Mr Cornara, manager of the transport firm that employed Mr Salhi, attached to a fence at the plant owned by US group Air Products, framed by black and white flags bearing Islamic slogans.
The body of Mr Cornara also bore signs of strangulation suggesting that he may have been killed at an unknown location prior to his decapitation.
Investigators searching Mr Salhi's home in Saint-Priest, near Lyon, seized a laptop, a tablet computer and a fake pistol but found no trace of explosives or radical propaganda.
"We don't know whether we're dealing with a fundamentalist who just lost it or a real terrorist," a source said.
Canada has seen the radicalisation of some of its citizens, with about 100 people thought to have gone to Syria to join the Islamic State group.
Politicians recently endorsed a new anti-terror law that boosts powers of Canada's spy agency amid concerns of attacks within the country.
