SEOUL (Reuters) – Around 4,000 recovered COVID-19 patients from a religious group at the centre of South Korea’s largest outbreak will donate plasma for research, an official said on Tuesday, a day after local officials filed a lawsuit against the church.

FILE PHOTO: A man wearing a mask walks past a branch of the Shincheonji Church of Jesus the Temple of the Tabernacle of the Testimony, amid rise in confirmed cases of the novel coronavirus disease COVID-19 in Daegu, South Korea, March 2, 2020. REUTERS/Kim Kyung-Hoon

In February and March, a massive outbreak among members of the Shincheonji Church of Jesus made South Korea the scene of the first large outbreak outside of China.

At least 5,213 of the country’s total 12,484 cases have been linked to the church outbreak, according to the Korea Centers for Disease Control and Prevention (KCDC).

Church founder Lee Man-hee had internally advised recovered members to donate their plasma, which is badly needed for coronavirus research, Shincheonji media coordinator Kim Young-eun told Reuters on Tuesday.

Many of recovered church members wanted to donate to express thanks to the government and medical staff, she said.

The city of Daegu – where most of the church infections were centred – filed a civil lawsuit against the church on Monday, seeking 100 billion won ($82.75 million) in damages.

Daegu authorities had previously filed a complaint against the church accusing it of not submitting a full list of members and facilities, and not cooperating with city health efforts.

Shincheonji says it fully complied with government efforts.

The National Institute of Health said 185 people have so far come forward to donate plasma as of Monday and said they were in talks with Shincheonji for donations.

South Korea health officials have said that in the absence of other treatments or vaccines, plasma therapy may be a way to lower the death rate, especially in critical patients.

At least 17 South Koreans have received the experimental therapy, which involves using plasma from recovered patients with antibodies to the virus, enabling the body to defend against the disease.

South Korea has reported 281 deaths from COVID-19.