According to SFVS, an emergency investigation was launched after 24 pigs on the farm of 19,500 in the village of Skabeikiai died in three days. It's a second time in recent years when such an outbreak is recorded on the company's farm.
All the remaining pigs on the Skabeikiai farm will be culled.
Saulius Leonavicius, director general of Idavang in Lithuania, says the way the virus managed to get into the safe complex is still unknown.
"The complex complies with the highest biosafety requirements, with all special protection measures in place and used. We still don’t know how the virus got into the complex. It's the key question we are looking the answer for," Leonavicius said in a statement.
Idavang says all 19,500 pigs are insured.
In the summer of 2014, a swine fever outbreak was recorded on the Idavang farm in the village of Rupinskai in the northwestern district of Ignalina, and around 19,000 pigs had to be culled.
An outbreak of swine fever was recorded on a small farm with 4 pigs in the town of Papile, Akmene District, and the Skabeikiai farm got into the 10-km monitoring zone and was temporarily barred from selling and transporting live stock, pork and its products.