The announcement came amid fresh clashes between police and protesters on the rain-soaked streets of Caracas.
A day earlier, Venezuela's Supreme Court banned Ortega from leaving the country and ordered her assets frozen ahead of a pretrial hearing scheduled for Tuesday.
An ally of embattled President Nicolas Maduro's requested the inquiry to determine if Ortega committed unspecified "grave errors while in her position" and if there is enough evidence for charges to be filed against her.
Ortega, a vocal critic of Maduro's government, could face a trial.
In a statement Thursday, Ortega's office said Antonio Benavides Torres, former commander of the national guard, has been charged in connection with "serious and systematic human rights violations" during the ongoing protests.
In 2015, the White House sanctioned Benavides Torres over
human rights abuses. Human Rights Watch has accused him and other high-level officials of failing to take steps to prevent or punish human rights violations.
Benavides Torres was removed from his national guard post last week and named head of government of the capital district.
The attorney general's statement referred to alleged abuses by authorities during more than 80 days of demonstrations. "In a great number of these incidents, there is evidence of excessive use of force in repressing protests," it said.
The political turmoil gripping the country took a surreal turn Tuesday night with an audacious attack by a police helicopter on the Supreme Court.
The chopper was found Wednesday
in a rural part of the country, but authorities said the aircraft's pilot remains on the run.
Ortega has recently accused Maduro's government of committing "state terrorism" by stripping citizens of their right to protest, trying them in military courts and carrying out raids without consulting courts. "We continue to witness the rupture of the constitutional order. The constitution keeps on being violated, and the government institutions are being dismantled," she said.
Pedro Carreño, the lawmaker who requested the pretrial hearing for Ortega, has told reporters he believes the attorney general is not in her right mind and will convene a medical board to assess her recent behavior.
"It is clear that this lady is not normal," Carreño said.
The United Nations on Friday called the high court decision to freeze Ortega's assets and ban her from leaving the country "deeply worrying."
It is also concerned that the court's constitutional chamber found her appointment of a deputy attorney general "to be null and avoid."
"Since March, the attorney general has taken important steps to defend human rights, documenting deaths during the wave of demonstrations, insisting on the need for due process and the importance of the separation of powers, and calling for people who have been arbitrarily detained to be immediately released," said Rupert Colville, spokesman for the UN high commissioner for human rights.
"We are concerned that the Supreme Court's decisions appear to seek to strip her office of its mandate and responsibilities as enshrined in the Venezuelan Constitution, and undermine the office's independence."
The helicopter involved in the Supreme Court attack was allegedly piloted by Oscar Perez, an officer in the country's investigative police force.
Before the attack began, a man who identified himself as Perez appeared in a video online saying an operation was underway to seize democracy back from Venezuela's "criminal government."
Flanked by armed men in military fatigues and balaclavas, the man claimed to be speaking on behalf of a coalition of military, police officers and civil officials.
As the helicopter strafed the court building and the Interior Ministry, attackers fired gunshots and lobbed grenades, officials said. It was unclear how a rogue police helicopter could have circled high-profile buildings in the capital without being shot down. Witnesses and local journalists said the assault went on for about two hours.
No one was injured, but the assault was a dramatic escalation of the months-long crisis engulfing the regime of Maduro, who called the attack an attempted coup.
None of those involved in the attack appear to have been tracked down. Venezuela has asked Interpol to issue a red notice for Perez, according to Néstor Luis Reverol, the county's minister of interior, justice and peace. A red notice alerts authorities in other countries, including border officials, that someone is wanted.
The helicopter was later found in the seaside state of Vargas, state-run news agency Agencia Venezolana de Noticias reported. Photos published on the verified Twitter feed for Vice President Tareck El Aissami show the helicopter in a clearing.
Months of chaos
Venezuela is in the throes of a political and humanitarian crisis that has brought thousands onto the streets in protests demanding a change of government.
On Thursday, protesters and authorities again clashed during a march to the nation's electoral headquarters, with police firing tear gas and making dozens of arrests, according to posts on social media.
Soaring inflation and widespread shortages of medicine, food and other essentials have infuriated many Venezuelans, who are struggling to afford basic necessities.
Oil revenue fueled Venezuela's economy under the late President Hugo Chavez, who was Maduro's mentor, but falling oil prices have made state subsidies unsustainable.
Anti-government protesters want Maduro to step down, accusing him of eroding democracy. Maduro has sent the Venezuelan military onto the streets to maintain order, leading to deadly clashes. According to the attorney general's office, at least 80 civilians have died in the unrest, including the point-blank shooting of a 22-year-old protester by a soldier
Two deaths Wednesday are also being investigated.
The government intimidates and restricts the media in Venezuela, taking CNN en Español off the air. It tightly controls visas for foreign journalists including CNN, arresting those who report from inside the country without proper permits.