The demolition firm dismantling a power station in Kent watched profits collapse into losses last year after a “global rout” in the prices of scrap metal.

Brown and Mason, known as BAM, which is behind the destruction of the former Kingsnorth power station in Hoo, was hit with losses of £4.7 million, having made profits of £1.2m a year earlier.

The company, which has its headquarters in Dartford, carried out a review of the profitability of all its contracts following the “drastic and unprecedented fall in prices of all metals”.

However, it found all its projects remain on course “to generate multi-million pound profits”.

Turnover increased 34% to £46.9m in the year to the end of April 2016, “demonstrating the group’s continuing ability to secure and fulfil large demolition contracts in the UK, underlining its position as a market leader”.

Metal prices have recovered since the period covered by its latest available accounts.

Managing director Nick Brown said: “During 2015 and into the first half of 2016, the industry witnessed an unprecedented global commodity rout.

“BAM was not immune to this and had to navigate through an environment where scrap prices were drastically lower.

“We are fortunate that careful and prudent management over the years meant that the company was strong enough to withstand this.”

He added: “As quickly as the prices fell, the rebound was equally strong.

“Key commodity prices have recovered to pre-crash levels and we are pleased to say the company has emerged from this with a contract pipeline which is stronger than ever, and with great optimism for the future.”

In the firm’s annual report, company secretary, Laura Hadden, said: “The group’s pipeline of projects remains strong on the back of further contract wins during the year and the directors anticipate further contract wins over the next 12 months.”

The firm, which employs about 340 people, safely demolished two 20,000-tonne boiler houses at the former Kingsnorth power station last month – with 200kg of explosives.

It will take around three months to process the enormous pile of debris from the 67m-high structures.