Former Lebanese Information Minister, Michel Samaha, who was convicted of smuggling explosives and planning attacks last year received an increased sentence of nine years and nine months on Friday, following his retrial.
Samaha, who has close ties to Syria's Bashar al Assad was detained in August 2012 and sentenced to four and a half years in 2015.
The court set the longer sentence at 13 years, but in Lebanon one year of imprisonment is equivalent to nine months.
He was freed on bail in January pending a retrial and confessed to the charges before the first sentence was handed down. He also gave details of a plot, allegedly devised with Syrian regime security chief Ali Malmuk.
Justice Minister at the time, Ashraf Rifi, had described the shorter sentence as a travesty of justice.
The case, which produced indictments against two Syrian regime officials, including a top general, exposed Lebanon's political division between parties that support and oppose Assad.
Syria is Lebanon's largest neighbour and before its civil war had long played a dominant role in the tiny Mediterranean country.
Rifi resigned in February, partly due to Samaha's release on bail, which he said showed the Lebanese Shia group Hezbollah, an ally of Assad, was causing paralysis in state institutions.
His bail was also cited by Saudi Arabia's Foreign Minister Adel al Jubeir as evidence of Hezbollah's growing clout in the country, as Riyadh cut aid to Lebanon as part of efforts to isolate its main regional rival Iran.