Billboards showing the faces of slain Colombian drug cartel chief Pablo Escobar and a leftist guerrilla leader have set off a controversy by asking: "Guess who has killed more police?"

Colombia's National Electoral Council ordered that the billboards, which were put up in the northwestern city of Medellin by former vice president Francisco Santos, be taken down immediately.

Santos, a cousin of President Juan Manuel Santos and a close ally of ex-president Alvaro Uribe, has said he hopes to run for the presidency in 2014.

But the electoral college said the billboards were "clear examples of electoral campaigning, and these type of ads are only permitted in the three months before elections are held."

Santos said his intent was "to generate debate about the victims of the FARC," he said referring to the leftist guerrilla group.

The FARC's leader Ivan Marquez, was pictured on the billboards along with Escobar, the notorious chief of the Medellin drug cartel chief killed in 1993.

Marquez is representing the FARC in peace talks in Havana with representatives of the Colombian government.

President Santos, who is eligible to run for re-election, is hoping to conclude a peace with the FARC that would end Latin America's longest insurgency by the end of this year.

Uribe, a hardliner who tried to defeat the FARC militarily during his 2002-2010 presidency, has opposed the peace talks.