A former soldier questioned by police investigating the 2012 murder of Claygate businessman Saad Al-Hilli and two family members in the French Alps has been found dead.

In an apparent suicide, the man, who has not been named, left a note saying he was “disturbed” by the police’s questioning, claiming he was made to feel “like a suspect” in the case.

French media have reported that the soldier was a 50-year-old former parachutist and trained marksman, who was found dead at his home in Ugine, south eastern France, on Tuesday evening. Mr Al-Hilli, 50, of Oaken Lane, his wife Iqbal, 47 and her mother Suhalia Al-Allaf, 74, were shot dead while on a caravan holiday in Lake Annecy in September 5, 2012.

All three victims received two bullets to the head through the window of their car.

The two Al-Hilli children, Zainab, then seven, and Zeena, then four, survived the attack.

Zeena escaped unharmed by cowering beneath her dead mother’s skirt and was not found by police until eight hours after the shooting.

Mr Al-Hilli’s older brother Zaid, 54, or Bray Court, North Parade, Chessington, was arrested in July 2013 on suspicion of conspiracy to commit murder, but was released without charge in January this year. A cyclist, Sylvain Mollier, 45, was also shot dead in the attack, close to the village of Chevaline.

It has been suggested that Mr Mollier was the main target of the attack.