A London solicitor at the centre of a dispute over alleged illegal file sharing could face a huge costs bill after a judge ruled that he had breached the code of conduct and ‘brought the legal profession into disrepute’.

Judge Birss, sitting in the Patent County Court, allowed the first stage of an application for wasted costs against Andrew Crossley and his firm ACS:Law last week.

Crossley sent thousands of letters on behalf of client Media CAT, a company that pursues alleged copyright infringers.

The correspondence demanded around £500 in compensation from people whom Media CAT claimed had illegally shared pornographic films via the internet.

Crossley brought court proceedings against 27 defendants, but attempted to discontinue the actions. Last month Birss formally struck out the proceedings, prompting some of the defendants to pursue Crossley for costs.

Birss ruled that Crossley had breached the Solicitors Code of Conduct by entering a prima facie ‘improper and champertous’ agreement with Media CAT, under which he would receive 65% of any damages collected from the alleged file sharers.

Under rule 2.04 of the code of conduct, a solicitor ‘must not enter into an agreement to receive a contingency fee for work done in prosecuting or defending any contentious proceedings’ before the court.

Birss said: ‘I am quite satisfied to the standard necessary for this stage of a wasted costs application that Mr Crossley is responsible for the basic agreements, and has thereby acted in breach of [the] Solicitors Code of Conduct.’

Birss said ACS:Law’s conduct was ‘chaotic and lamentable’, and that Crossley had lent his assistance to proceedings that were an abuse of the process of the court and ‘brought the legal profession into disrepute’.

He said: ‘This was not the behaviour of a solicitor advancing a normal piece of litigation. I do not doubt that this led to unnecessarily incurred costs.’

Crossley will appear before the Solicitors Disciplinary Tribunal later this year.

A spokeswoman for the Solicitors Regulation Authority said: ‘The judgment supports our concerns about the effect this sort of correspondence has on the public.’

Mills & Reeve, which represented Crossley and ACS:Law, declined to comment.

Michael Forrester, intellectual property partner at national firm Ralli, who represented five of the defendants, said his clients’ costs amounted to £80,000.