MEXICO CITY, April 10 (Reuters) - A Mexican judge has overturned a 5-year prison sentence against the son of Mexico's most wanted drug trafficker, Joaquin "Shorty" Guzman, and ordered him freed from jail, local media reported on Thursday.

The judge said there was not enough evidence for the conviction of Archivaldo Ivan Guzman, sentenced in February after being found guilty of money laundering.

Seven people were killed by unidentified gunmen in the western city of Guadalajara last month in the offices of a law firm believed to have been handling the defense of several people accused of drug offenses, including Guzman's case.

Joaquin Guzman heads an alliance of narco smugglers based in Sinaloa state and is Mexico's most wanted criminal. He escaped from a high security jail in 2001.

He is locked in a war with the Gulf Cartel from northeastern Mexico. Drug killings totaled more than 2,500 in 2007 and are already above 850 so far this year.

President Felipe Calderon deployed some 25,000 soldiers and federal police to drug hot spots across Mexico after taking power in late 2006. (Reporting by Cyntia Barrera Diaz, editing by Todd Eastham)

AlertNet news is provided by