The International Red Cross says one of its workers was abducted and killed by unidentified gunmen in the country's volatile north.
Officials say 40-year-old Sooriyakanthy Thavarajah was taken from his home in the northern Jaffna peninsula on Friday. His body was discovered on Sunday.
The Red Cross is demanding Sri Lankan authorities investigate the killing.
Earlier this year, two Red Cross workers were killed after being abducted from a railway station in the capital, Colombo.
In other news, Sri Lankan officials will meet with delegations from India and Russia this week to discuss the possible purchase of weaponry.
The discussions with India are expected to focus on improving Sri Lanka's air defense system, as the military steps up its fight against Tamil Tiger rebels.
The rebel group carried out its first aerial assaults on government targets early this year. The most recent attack was against a Sri Lankan military base in October.
Tamil Tigers have been fighting for an independent homeland for nearly 25 years, claiming discrimination by Sri Lanka's majority-Sinhalese government.