Jewish museum attack: Police want to question man spotted in CCTV footage with alleged gunman

The suspect was seen walking with another man at a station four days after attack

Mehdi Nemmouche has been in custody since his arrest in France soon after the Brussels killing in May (AFP/Getty Images)

Authorities in Belgium are looking for a possible accomplice to the gunman who is charged with killing four people at a Jewish Museum in Brussels last year.

Police want to question a man, who has a close-shaven head, that was spotted in CCTV footage believed to have been walking with Mehdi Nemmouche at a railway station in Brussels four days after the attack that occurred on 24 May.

The video released by police last week, the day after anti-terror raids in the eastern Belgian town of Verviers in which two suspects died in a shoot-out, shows a man walking alongside a blurred-out individual.

Nemmouche, a 29-year-old French man of Algerian origin, was arrested in Marseille, south of France, during a routine customs check and was extradited to the Belgian capital on 29 July where he remains in custody.

His bag was reported to have contained a Kalashnikov rifle, a revolver and ammunition similar to those used in the attack in Belgium.

Nicolas Henin, a journalist captured and tortured in a basement of a former hospital in Syria, claims that Nemmouche was one of his captors from July to December 2013 before he was released in April last year.

The terror threat in Belgium has been raised to three and has deployed soldiers to guard potential targets amid fears of those returning to Europe from fighting in Syria.