The cyclist who stumbled across the bodies of a British family killed in a remote spot in the French Alps said Thursday the blood-soaked crime scene looked like something out of a Hollywood script.

Saad al-Hilli, his wife Iqbal, her mother, and an unrelated French cyclist were shot dead just over one week ago in a forested area near France's Lake Annecy in slayings that have baffled police.

William Brett Martin, the cyclist who first raised the alarm, told BBC television that what he saw on was "the sort of thing you would never in your life expect to come across."

"It seemed to me just like a Hollywood scene," he said. "But unfortunately it was real life."

Martin's comments were broadcast just as French prosecutor Eric Maillaud told reporters the key to solving the execution-style killings was in the U.K. — suggesting some connection to the al-Hilli family's personal or professional life in the southern English county of Surrey, where the family settled after leaving Iraq.

Speculation has swirled around an alleged family dispute, al-Hilli's job, or the family's Middle Eastern origins as potential motives for the slayings. Family friends have described a dispute between Saad al-Hilli and his brother Zaid over their father's inheritance, although French authorities have said Zaid denies that there was a disagreement.

Journalists have asked about the possibility of a hate crime or a robbery gone wrong, but Maillaud told reporters at a Surrey police station the fact that the al-Hillis died in Annecy was just a twist of fate.

"The cause and the explanation are here," he said.

Martin, a former Royal Air Force member, told the BBC he was out cycling in the French Alps "just like any other day" when he came across the al-Hilli family's car revving its engine and spinning its wheels idly. Just in front, he said, a little girl was stumbling around.

"She looked like she was falling over, larking about like a child would," he said.

When he came closer, he could see that something was wrong. The girl — now identified as the al-Hillis' seven-year-old daughter, Zaina — was covered in blood and had "obvious head injuries." Zaina survived but was badly hurt while her 4-year-old sister Zeena was left unharmed.

At first, he said, he thought there had been an accident. But the dead French cyclist nearby was in a strange position and the punctures in the car's crumpled window appeared to be bullet holes. When he approached the car, it was clear the family had been shot to death.

"If you've seen CSI Miami, it was pretty much what you'd imagine a set from CSI Miami to be like," he told the BBC, referring to the popular U.S. crime show. "There was a lot of blood and heads with bullet holes in them."

Martin said he had no idea — "none at all" — that there was another person in the car. The 4-year-old Zeena would lie undiscovered inside the car for another eight hours — apparently too shocked or scared to move.

Martin said he tried to call for help but couldn't get through.

"Of all the moments in the world to have no signal on your mobile phone that was it," he told the BBC, adding that he eventually had to leave Zaina to go seek help.

Zeena is now with relatives in Britain and Zaina is still recovering from her injuries in a French hospital.

Martin's U.K. telephone number was unlisted and few other contact details could immediately be located.