Two siblings have spoken about the heartache of watching an elderly loved one stubbornly pour up to $100,000 into a Nigeria-based romance scam despite their protests.

The pair did not wish to be named, believing the toll the story would take on relationships within the family would be too great, but told the Herald about how their father, who is in his 80s, faithfully sends large sums of money to a woman in Nigeria every month.

And there was nothing they could do to stop it.

The octogenarian had been making transactions for more than two years.