Colombia's powerful former President Alvaro Uribe has resigned his Senate seat to face a bribery and fraud investigation in the Supreme Court.
He is seen as the power behind the country's incoming President, Ivan Duque, who is due to take office in August.
Mr Uribe, who was president from 2002 to 2010, faces charges of making false accusations and witness tampering.
It is the first time a Colombian court has asked an ex-president to testify.
Alvaro Uribe's exit from the Senate removes a vocal critic of the peace deal signed with the Farc rebels in 2016, which ended more than 50 years of armed conflict.
His eight-year presidency was marked by his hard-line stance against the guerillas, who killed his father in 1983. Mr Aribe has always called for tougher treatment for former Farc rebels in the courts.
Why did Mr Uribe resign?
In a Tweet on Tuesday, Mr Uribe said he felt "morally impeded to be a senator" and explained that he was resigning to ensure that "my defence does not interfere with the work of the Senate".
However, his decision has prompted press speculation about his real reasons for leaving office.
In Colombia, the Supreme Court is in charge of investigations against elected officials, while ordinary citizens are investigated by the Prosecutor General's Office.
According to his critics, Mr Uribe's resignation will help him to avoid being called before the Supreme Court.
The cases against him are likely to be transferred to Colombia's notoriously corrupt and inefficient Public Prosecution Service.
Why is Mr Uribe being investigated?
The case that led to the Supreme Court investigation began in 2012, when the former president accused leftwing lawmaker Ivan Cepeda of orchestrating a plot to link him to right-wing paramilitary groups.
But the Supreme Court dismissed the charges against Mr Cepeda and said that it appeared Mr Uribe had threatened witnesses.
Mr Cepeda hailed the Supreme Court's decision to press charges against Mr Uribe as a historical milestone.
"Uribe was considered untouchable and all powerful until yesterday. This marks a very important precedent," he said.
Alvaro Uribe and his family have long been accused of paramilitary involvement but previous investigations have not borne fruit. The family has denied all links.
Mr Uribe's brother, Santiago, is currently awaiting trial for allegedly running a paramilitary group known as the Twelve Apostles.
Paramilitary groups in Colombia were originally funded by landowners to protect them from left-wing rebel groups such as the Farc.
However, they later became feared death squads linked to rural massacres, drug trafficking and sexual violence.