The founders of flopcom Digital Entertainment Network (DEN) are still languishing in a Spanish jail, and investigators in the US are stepping up efforts to bring them home to face sex offence charges.

DEN co-founders Marc Collins-Rector, Chad Shackley and Brock Pierce were arrested in June on an international warrant after being indicted in New Jersey on five counts of transporting a minor across state lines for the purpose of engaging in sexual acts.

The company raised $75m through an Initial Public Offer, but collapsed as allegations of its founders' conduct hit the media. DEN's assets were sold at auction for $105,000 this summer.

The men fled to Spain where they were arrested by Spanish police who found "enormous amounts of child porn" at their villa.

All three are likely to face Spanish charges, but US police have stated that Spain will let the US charge them first, according to the New York Post.

Collins-Rector, Shackley and Pierce already face a $4.5m default judgement over offences with teenaged boys in the Beverly Hills and west Los Angeles area dating back to the early 1990s, after losing a civil court case brought by victims.