San Francisco - A former internet spam king who escaped from a low security prison earlier this week has killed himself and his family in an apparent murder-suicide police said Friday.

The bodies of convicted spammer Edward "Eddie" Davidson, 35, his wife and 3-year-old daughter were found in a parked car near their former farmhouse about 40 kilometres east of Denver, Colorado. His older teenage daughter was shot in the neck but managed to escape, while his seven-month old baby was left unharmed in the car.

The Denver Post quoted the surviving daughter as saying Davidson lured his wife and the family to the fatal meeting on Thursday by promising that he just wanted to see them before turning himself in to police.

Police had been on the lookout for the couple since Sunday, when Davidson's wife was believed to have helped him escape from a minimum-security federal prison in Florence, 140 kilometres south of Denver.

Davidson was sentenced in April to 21 months in jail and ordered to pay more than 700,000 dollars in fines after pleading guilty to spam charges and tax evasion.

According to prosecutors he earned millions of dollars from bombarding people with unwanted emails hawking everything from perfume to penny stocks. (dpa)