Blue-eyed, curly-haired Cyril Jacquet was the perfect reality show participant. Young, attractive, outgoing and ambitious, he and his girlfriend, Paola Alberdi, were determined to win a new Spanish TV show called Around the World.

The show, on the Antena 3 channel, involves couples racing each other around the globe. It promised adventure, a €200,000 (£178,000) prize and, inevitably, fame.

Jacquet did not seem to realise, however, that fans of the show would inevitably start putting his name into their internet search engines and finding out a little bit more about him.

So it was that, on Sunday night, he returned from Venice and abandoned the show after programme-makers questioned him about internet rumours that as a 15-year-old he had murdered his mother and father.

"I will always hold my head high," Cyril said, before he and Paola waved a tear-filled goodbye.

"People change," he added.

Antena 3, which devoted part of the Sunday-night to Monday-morning show to the news, said it had no idea that one of its contestants was a parricide.

"The programme did not know," a ­presenter told viewers. "After we checked the facts of the case we brought them back to Spain to protect them from media attention."

In 1994, Jacquet killed his mother with three shots from his father's automatic pistol after she entered the family home. A few hours later, Jacquet used the remaining seven bullets for his father.

He eventually confessed to the double killing and served three years in a youth detention centre. Under Spanish law he has no criminal record since he was a minor at the time of the double killing.

Jacquet, now an airline cabin crew worker, blamed the media and "undesirable" people for his decision to abandon the show. "They don't let you leave the past behind," he complained. "I don't want to keep giving them the excuse to lynch me."

Paola, who said she had always known about her boyfriend's past, said: "It bothers me a lot that we have to go because someone wants to pour shit on someone else's life. I know he is strong. If he has got to where he has, it is because he can handle anything."