Prosecutors had wanted to take Fico into custody to prevent him from influencing witnesses.
Slovakia’s parliament has refused to waive immunity rules and allow the detention of former Prime Minister Robert Fico, who has been charged with creating a criminal group.
Only 74 of the 150 lawmakers in the National Council voted in favour of the prosecution request, two short of the majority needed.
Prosecutors had said they wanted to take Fico into custody to prevent him from influencing witnesses.
Fico has denied any wrongdoing, saying the charges brought last month were politically motivated. He also claimed that the case against him and his former interior minister, Robert Kalinak, was designed to destroy the political opposition.
Fico currently has immunity from prosecution as a lawmaker for his leftist opposition Smer-Social Democracy party. Kalinak, who was detained, currently works as a lawyer.
Slovakia’s four-party ruling coalition has a comfortable parliamentary majority, so the outcome of Wednesday's vote reflected a split in the coalition.
The country's government made fighting corruption a key policy issue since it took power after the 2020 general election. A number of senior officials, police officers, judges, prosecutors, politicians and business people have recently been charged with criminal offences.
Fico, who is considered a populist politician, twice served as the prime minister from 2006 to 2010 and again from 2012 to 2018.
He resigned after the 2018 slayings of investigative journalist Jan Kuciak and his fiancee, Martina Kusnirova.
Kuciak had been investigating possible government corruption when he was killed and his death prompted major street protests and a political crisis that led to the government’s collapse.