Mr Barrowman and his business partners had been accused over a £16 million deal to purchase a cable factory that went on to file for bankruptcy.

The Baroness’ husband has been linked to multiple tax-avoidance companies in the past. It was alleged that Mr Barrowman and his five associated had defrauded the Spanish Treasury by claiming tax relief on part of a six-figure “consultancy fee” in the company’s annual return, The Times reports.

Mr Barrowman admitted to playing a “senior” role in the purchase of the French-owned factory near Santander, however many of the defendants denied accusations that they did not work on the deal and that the invoice had been fabricated to obtain money from the cable firm.

Three Spanish judges released a ruling which concluded there was “abundant documentation” that services were provided by Mr Barrowman and his associates, but described the sum paid as “disproportionate”. Nevertheless, this did not imply criminal wrongdoing.

The judges also ruled that prosecutors had failed to prove that money paid to a company linked to Mr Barrowman had been sent to an offshore account.