BOGOTA--Colombia's top administrative court on Friday began hearings that could be long and contentious about proposals for hydraulic fracturing in the country.

The public hearings in the Council of State, which is tasked with ruling on administrative matters, stem from a decision made late last year to temporarily suspend regulations for development of unconventional oil.

Hydraulic fracturing is not yet in use in Colombia. While there is no law against the practice, the government says regulations are needed before it can be used. It’s possible use has sparked vitriolic debate among lawmakers, activists, officials and regular citizens about whether it could cause pollution or other environmental harms.

"We consider this high-impact litigation," Magistrate Ramiro Pazos told Reuters after the largely procedural hearing. "It's an issue of extreme importance for the country."

Six magistrates could rule next month on whether the suspension should continue, Pazos said, while evidence gathering on whether hydraulic fracturing should go ahead will take until the end of the year.

The next hearing, which will include witness testimony, is scheduled for July.

The tribunal's decision to suspend the regulations came after environmental lawyer Esteban Lagos, with support from the Universidad del Norte college, anti-fracking activists and a leftist lawmaker, filed a suit against the energy ministry to halt potential use of the technique.

Lagos, representing himself, said he was optimistic about the process.

State-run oil company Ecopetrol is acting as a co-defendant and asked the court to lift the suspension measure so a pilot project can proceed.

The company has applied for several licenses and is looking to spend $500 million on exploring unconventional deposits over the next three years.

Hydraulic fracturing could nearly triple Colombia's reserves of crude and gas, the government has said.

An expert commission convened by the government to study hydraulic fracturing recommended strict monitoring of three pilot projects to determine whether the technique should be widely used.

Three commission members will be able to testify in the case, Pazos ruled.

Onshore