Justice Secretary Raul Gonzales said he has also ordered the issuance of a hold departure order for the suspects whom he refused to identify.
"I cannot give you the identities of the suspects as it will jeopardize our investigation... but I am sure they are working with the government there in Mindanao," Gonzalez told The STAR in a cellular phone interview.
When asked if he was referring to Suami Sekak, a former Region 12 director of the Department of Agriculture, Gonzales said, "He was not part of our investigation, but I am not saying he is already cleared of any possible involvement."
Gonzales’ statement disputed an earlier report of the National Bureau of Investigation (NBI) which tagged Sekak as the alleged mastermind in the Maundy Thursday killing of Esperat.
The hard-hitting columnist of the Midland Review was shot by a lone assassin in her house in Barangay New Isabela in Tacurong City.
A DOJ insider, however, told The STAR that the gunslaying might have something to do with Esperat’s expose about an anomalous multibillion-peso transaction involving a finance officer of a government agency.
"Malalim ang kasong ito... tinitiyak namin na sa darating na araw siya talaga ang ituturo na nagpapatay kay Esperat (This case is deep... we are sure that in the coming days, this individual will be pinpointed as the one who ordered Esperat killed)," he said.
The DOJ insider added that the public official has unexplained wealth, boasting of several luxury cars and a house "na parang palasyo (like a palace)."
"Balita nga namin ‘yong anak niya sa elementary gumagastos daw ng P2,000 araw-araw (We heard that his son in elementary school reportedly spends P2,000 every day)," he said.
Gonzales said the Manila prosecutors will assist Kidapawan City prosecutor Al Calica to go over the extra-judicial statements of four other suspects who were earlier arrested by the regional police led by Chief Superintendent Antonio Billones.
"We will not stop the investigation unless the mastermind in the killing is arrested," said Gonzales, whom several media organizations here hailed last month for ordering a speedy investigation into the murders of broadcasters Ely Binoya and Jonathan Abayon and for extending financial assistance to their families.
Billones identified the four detained suspects as Randy Grecia, Jerry Cabayog, the alleged gunman; Rowie Burcia and Estanislao Bismanos, who admitted during police interrogation that a certain "Madam" from the DA regional office gave them the money to kill Esperat.