Investors who bought a bond promising annual returns of 7.5pc from renewable energy company Wind Prospect Group face a three year wait to have their capital returned.

The “mini-bonds”, called ReBonds, were issued by the company in 2011 and were due to pay the annual interest before investors were able to request their capital back last year. But bondholders have been in limbo since the summer when interest payments and redemption requests were suspended.

At the time the firm said there would be a “three month moratorium” but, as Telegraph Money reported in January, six months later and interest and capital remains unpaid.

In an update to investors, seen by Telegraph Money, the firm said it will take three years for all bonds to be redeemed under a restructuring plan.

Interest payments, both future payments and those that are overdue, will be serviced, the company said.

The proposal needs to be given the green light by 75pc of the bondholders, of which there are around 300. It said it could not guarantee to meet redemption requests, while noting that a big rush to the exit “could call into question the viability of Wind Prospect Bonds PLC, destroying value for all ReBond holders”.

Why the bond is facing difficulties

The bonds supplied funding to Wind Prospect, which builds and provides services to renewable energy projects. The company said its model had been hit by reductions to energy subsidies announced in the Summer Budget.