An investment fund headed up by Ukip donor Christopher Mills has lost £20 million after the company behind rock magazine Metal Hammer went bust.

Harwood Capital's North Atlantic Smaller Companies Investment Trust (Nascit) held a stake in Metal Hammer's parent firm Team Rock before it fell into administration in December.

Mr Mills said: "There has been a massive decline in print advertising and we just couldn't keep sustaining millions in losses. Our £20 million investment has been wiped out."

Read more: Team Rock brands sold to Future plc. in £800,000 deal

Accounts filed at Companies House show that Nascit led a £4.5 million fundraising round in October 2015 and provided an £8.9 million loan to Team Rock, which it later waived and converted into equity.

Mr Mills, who has an estimated fortune of more than £200 million, has donated hundreds of thousands to Ukip through Growth Financial Services, according to the Electoral Commission website. He now serves as the militantly pro-Brexit party's business spokesman.

Team Rock, which also housed Classic Rock, Prog, Blues and Golden Gods, was on Monday sold to publishing giant Future for £800,000. It had racked up losses of £8.8 million in 2015 and had debts of more than £11 million.

Read more: Team Rock brands sold to Future plc. in £800,000 deal

The deal represents a coup for Future, which had sold the stable to Team Rock in 2013 for £10.2 million.

However, the bulk of its approximately 80 staff members have been axed.

Another major backer to lose out from the deal was Scottish Enterprise, the country's main economic development agency. It had also participated in Team Rock's 2015 fundraising.

Tom MacLennan, joint administrator and partner with FRP Advisory, said: "We are delighted to have sold the assets of Team Rock Limited to Future plc and wish the new owners every success.

Read more: Team Rock brands sold to Future plc. in £800,000 deal

"The deal took just three weeks to conclude, during which time FRP Advisory received extensive support for our efforts to find a buyer, for which we are very grateful."