Nairobi, Dec. 17 -- Thousands of Kenyans are alleging foul play after a cryptocurrency platform promoted by a senior Seventh-day Adventist (SDA) pastor collapsed, wiping out investments estimated to be in the millions of shillings.

Users of the crypto and forex trading platform known as Optcoin over the weekend woke up to find the platform had disappeared, with users being directed to a new platform that required at least Sh24,000 as a registration fee, allegedly to unlock the lost funds from the collapsed platform.

Many of the victims claim to have been introduced to the platform by a popular SDA pastor known as Paul Mwangi, who is the former executive director of the Central Kenya Conference of the church, which comprises congregation...