BOGOTA - Colombia's justice minister resigned on Friday over a controversial reform measure into which lawmakers have slipped provisions that could dismiss cases against politicians with links to right-wing paramilitary groups and allow others to go free.

The scandal erupted after congressmen changed a bill aimed at modernizing the overburdened legal system during the reconciliation of the Senate and House drafts - raising questions about the lingering influence of illegal armed groups.

President Juan Manuel Santos sent the legislation back to Congress on Friday. It was the first time a president had done so since Colombia's 1991 constitution.

"The events of recent days will not let me - because it goes against my principles - continue forward," Minister Juan Carlos Esguerra told reporters, after only around a year in office.

"We do not have, neither I nor my staff, guilt about what happened with the inclusion of inappropriate texts," he said.

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