Reuters reports that the case was identified in the eastern state of Brandenburg on 28 September.
There have been 36 confirmed cases since the first one on 10 September. All were in wild animals with no farm pigs affected, the ministry said.
All have been found in the region of the first discovery in the Brandenburg area.
Germany's Friedrich-Loeffler scientific institute confirmed the latest animal had ASF, the ministry said.
China and a series of other pork buyers banned imports of German pork this month after the first case was confirmed, causing Chinese pork prices to surge.