A man lights on a candle on the Champs Elysees Avenue the day after a policeman was killed and two others were wounded in a shooting incident in Paris, France, April 21, 2017. The banner reads "With all my heart with the police, Long live France". REUTERS/Charles Platiau

PARIS (Reuters) - A man believed to have been an accomplice of the shooter who killed a policeman on Paris’ Champs Elysees in April was placed under a formal investigation and remanded in custody, a judicial source said on Saturday.

His DNA was found on the weapon used by the shooter, identified as Karim Cheurfi, who had opened fire on a police vehicle parked on the famous avenue in Paris, killing one officer and injuring two others before being shot dead.

The man arrested was unknown to anti-terrorist services, the source said.