A small toy figure is seen on representations of the Bitcoin virtual currency in this illustration picture, December 26, 2017. REUTERS/Dado Ruvic/Illustration/Files

LONDON: An anonymous benefactor has donated $5 million (3.53 million pounds) in bitcoin to the California-based Open Medicine Foundation, the non-profit research organisation said on Friday.

The OMF said it had received $4 million on Friday ? having received $1 million from the same donor last month ? via the account that it holds with BitPay, a bitcoin payments firm that converted the donation into US dollars.

The money came from an anonymous donor calling themselves ?Pine? from the Pineapple Fund, whose website says that it has already donated around $37 million anonymously to various charities and projects. The fund intends to donate $86 million in total, according to the website.

?Donating $86 million of bitcoins to charity because once you have enough money, money doesn?t matter,? the website states. It also says the fund holds one of the top-250 richest bitcoin wallets in the world, with ?Pine? having got into the market early.

Bitcoin allows money to be sent anonymously across a peer-to-peer global network, with no intermediaries needed to validate or process transactions. That has made it attractive to those who want to keep their identity secret, including those buying and selling illegal goods and services on the internet.

OMF set up its BitPay around a year ago to enable anonymous donations. Until now, though, the take-up has been low, with the total bitcoin donated in the thousands of dollars.

?This significant donation will help OMF accelerate and expand current research into ME (myalgic encephalomyelitis), CFS (chronic fatigue syndrome) and other chronic complex diseases and to keep fighting for a better future for patients,? said Linda Tannenbaum, founder and president of OMF.

Tannenbaum said OMF had conversations back and forth with the donor, but she did not know his or her identity.

?I?ve recently received letters of support from esteemed academics in the field strongly supporting OMF, and that helped me make the decision!? wrote ?Pine? in one message.