French police outside kosher supermarket in eastern Paris
French police outside kosher supermarket in eastern ParisReuters

French authorities have asked their US counterparts to help identify a person who appears to have given orders to one of the jihadist gunmen during the Paris terror attacks in January that left 17 dead, a source said Tuesday.

The mystery person contacted Amedy Coulibaly - who shot dead a policewoman and killed four shoppers in a Jewish supermarket - by email a day after his accomplices Said and Cherif Kouachi gunned down 12 people at the Charlie Hebdo magazine, the source said.

"If possible find and work with good dudes," the person tells Coulibaly in a message delivered on January 8"No friends possible, work alone, preference for the first thing planned."

"Go to the easiest and most secure and biggest number to start again several times," the person says, pointing to the possibility of acting in "suburbs if problem in center."

The emailer then provides Coulibaly with the steps to take to use a new email address created just hours before, that belongs to a messaging service managed by a company based in Pennsylvania in the United States, said the source close to the case, who refused to be named.

French investigators notified US authorities on January 29, and in June asked them to give them any information they have on the account.

The email exchanges were discovered on Coulibaly's laptop on January 9 at the Hyper Cacher Jewish supermarket, after he was gunned down by security forces.

The gunman and the mystery messenger both had the access codes for the same mailbox, which meant they never sent emails but put them in the drafts section for the other person to check, before deleting them.

French authorities has been on high alert since the deadly terror attacks in January.

AFP contributed to this report.