Lilian Lepere, a 27-year-old graphic designer, risked his life hiding in a cardboard box under a sink and texting information to the police while only metres from the armed brothers, Chérif and Saïd Kouachi.

Lepere, an employee of the family-run print works where the pair had burst into while on the run, sent tactical information to the police while hiding under the sink in the upstairs canteen for seven hours. A source told the AFP news agency that Lepere was “terrified” but managed to continue his secret communications undetected.

The Paris prosecutor, François Molins, told reporters that Lepere had sent “tactical elements such as his location inside the premises” as he listened to the gunmen talking and was able to relay what he could hear to the police.

When the siege started, Lepere sent a text message to his father asking him to get help. “I am hidden on the first floor. I think they have killed everyone. Tell the police to intervene,” he wrote.

Michele Catalano, the owner of the printing business who was taken prisoner by the brothers as they holed up at his office on an industrial estate in Dammartin-en-Goële, had spotted them armed with assault rifles and a rocket launcher. Knowing that he and his employee could not both hide from the killers, he ordered Lepere to seek refuge in the rear of the building.

Facebook Twitter Pinterest A man describes how he hid in a cupboard for more than eight hours to remain concealed as the gunmen responsible for the attack on Charlie Hebdo were inches away.

“I could immediately see there was a situation of danger. I told my employee to hide. I knew two of us couldn’t hide. At that point I thought that was the end. They came in, they weren’t aggressive. They said: ‘Don’t worry, we just want to come in.’”

He offered the intruders a drink and made coffee for them before one of his suppliers arrived at around 9pm. “I told those people that my supplier really had nothing to do there so could they let him go, so they did. So then we went down and went towards my supplier. I told him to leave so he immediately understood the situation so he left.”

He said he was worried that the Kouachis would find his employee’s hiding place. “I didn’t know where Lilian was hidden. I knew he was hidden but I had no idea where. I didn’t want them to go to the end of the building.”

After the brothers had emerged from the building and opened fire before being killed, police drove an armoured car into the building to free Lepere.

He was taken to police headquarters, where he was quickly reunited with his family feeling “shocked” but “OK”.