Detectives are seeking new leads in the case of the British family gunned down in the French Alps last September.
No arrests have yet been made over the deaths of engineer Saad al-Hilli, his wife, mother-in-law and a French cyclist.
Police are looking for a 4x4 vehicle, possibly a grey, black or dark coloured BMW X5, was being driven on the Combre d'Ire Road, Chevaline at around 3.20pm on September 5.
Eric Maillaud, the Annecy prosecutor who is leading the inquiry, has admitted that the case may never be solved.
It was recently reported that French police contaminated vital evidence from the crime scene.
Saad Al-Hilli, 50, died alongside his wife Ikbal, 47, and his mother-in-law Suhalia Al-Allaf, 74, in their BMW car.
The al-Hillis' four-year-old daughter Zeena lay undiscovered under her mother's body for eight hours after the shooting, while sister Zainab, 7, suffered serious injures after being shot.
Sylvain Mollier, a 45-year-old French cyclist, was also killed.
The investigation featured on BBC Crimewatch this evening.