BOGOTA, (Reuters) - The current Colombia head of coal miner Drummond Co Inc DRMND.UL and his predecessor will be tried for allegedly funding rightwing paramilitaries, the country's attorney general's office said yesterday, as the U.S.-based company denied any wrongdoing by the executives.

There is "abundant proof" current head Jose Miguel Linares, who took up his post in 2013 after serving as vicepresident of legal, and Augusto Jimenez, who headed the company's Colombia operations between 1990 and 2012, conspired to finance a paramilitary group, the prosecutor said in a statement.

"Linares Martinez and Jimenez Mejia, between 1996 and 2001, increased the value of a food provision contract with a provider company to obtain additional resources and use them to cover previously-agreed illegal obligations with...the United Self-Defense Forces of Colombia (AUC)," the statement said.

The effort was a bid to protect assets and ensure the free operation of Drummond's mine in Cesar province, the statement added. Drummond rejected the accusations, saying in its own statement that they are the product of "a cartel of false witnesses."

"These accusations are not backed up with credible proof and are based, principally, on false declarations by convicted criminals, who receive payments for testimony," the company said, without providing further details.

The company is confident evidence will demonstrate Linares' and Jimenez's innocence, it added.

The case is a "moral triumph," said Joris van de Sandt of Dutch non-governmental organization PAX, which has campaigned to raise awareness over alleged wrongdoings by Drummond, which the company has always denied.

Drummond - Colombia's largest producer of thermal coal - has three mining contracts in the country and also holds a port concession on the Caribbean coast.

It expects to export around 30 million tons of coal this year, Linares said this week.

Paramilitary groups emerged in the 1980s, funded by landowners, merchants and drug traffickers to defend themselves from attacks by leftist guerrillas.

Paramilitary groups - accused of murders, rapes, torture and other crimes - demobilized under a peace deal in the 2000s, though many members later formed crime gangs.