Two other crew from the 3,400-dwt Birthe Theresi (built 1995, ex Birthe Theresa) neededmedical attention in Latvia last week.
Latvianauthorities did not give details on the poisoning, but Moscow rescueauthorities said the cause was methanol.
One man was airlifted from the ship on 12 June, but a colleague was alreadydead.
A third seafarer became ill the following day.
An investigation has begun.
The vessel is operated by Ramava of Kaliningrad.
