Israel nuclear whistle-blower facing jail-stint once again
Vanunu, who was slapped with a series of restraining orders upon his release in 2004, was convicted of meeting with two US nationals in Jerusalem in 2013 without having permission to do so.
He was cleared of two other charges, one of which related to an interview he gave to Israel's Channel 2 television in 2015, and will be sentenced in two months, a court statement said.
Vanunu's conviction was ordered on January 18.
However, the ruling was not made public until Monday.
A sentencing hearing has been set for March 14.
The former nuclear technician was jailed in 1986 for disclosing the inner workings of Israel's Dimona nuclear plant to Britain's The Sunday Times newspaper.
Vanunu spent more than 10 years of his sentence in solitary confinement.
The former nuclear technician has landed himself back in prison on several occasions since his 2004 release, for breaching his release conditions.