A 94-year-old peaceful protester who won an eight-year legal battle to have his details removed from a police “extremism” database has vowed to continue campaigning.

The European Court of Human Rights (ECHR) handed down the ruling in the case of John Catt v the United Kingdom on Thursday.

Despite having no criminal record, requests by the war veteran and political campaigner from Brighton, East Sussex, to have his personal details and information about his attendance at various protests removed from police records were refused.

Speaking to Press Association, Mr Catt said he was “immensely pleased” with the outcome of the case and felt this was an important ruling for freedom of expression, adding: “This shows they were wrong to keep the details.

“It has taken such a long time.”

He accused police of a “conceited culture” because they were tasked with upholding the law, adding: “I have always had a determination to speak up for myself and speak out about injustices in life.

“I will still continue campaigning.”

Mr Catt previously described how his fight was “for the sake of other innocent people whose lawful political activities are being monitored by the state” and he would not give up.

He said: “This is an example of the erosion of freedom and a violation of private life. It is abusive collecting data and it is data control.”

His daughter Linda spoke of her “relief” that the lengthy legal battle was over, adding: “It strengthened his resolve to get justice and he has never given up.

“He did want to find out – we’re pleased that he’s alive to hear it.”

Mr Catt vowed to take his battle to Europe after Supreme Court justices overturned an earlier ruling in his favour.

He argued he was not involved in criminality, the continuing retention of data about him on the National Domestic Extremism Database was unlawful and breached his right to privacy under Article 8 of the European Convention on Human Rights.

Mr Catt first took legal action after the Association of Chief Police Officers (Acpo) refused his request to permanently delete all the data about him.

The database is maintained by the National Public Order Intelligence Unit, originally under the supervision of Acpo, and now under the responsibility of the Metropolitan Police Commissioner.

In March 2013, Mr Catt won his case at the Court of Appeal after a defeat at the High Court the previous year.

Court of Appeal judges said the information about Mr Catt was at first retained lawfully, but ruled it was held for a “disproportionate” length of time, violating Article 8 of the European Convention on Human Rights.

But then the UK’s highest court found in favour of police lawyers who said continuing to keep the details was still lawful.

The ECHR disagreed and in its judgment said: “The quality of the relevant legal framework was not adequate in a context such as the present one, and therefore the interference was not ‘in accordance with the law’ within the meaning of Article 8.

“This finding is sufficient to conclude that there has been a violation of Article 8.”

Mr Catt’s lawyer Shamik Dutta, from firm Bhatt Murphy, said: “This ruling sets an important precedent that it is unlawful for governments across Europe to label citizens engaged in peaceful protest domestic extremists and put them on a searchable database for a potentially indefinite period.”

Mr Dutta said the ruling showed the system had “failed” and the police should be “focusing their resources more sensibly”.

He said it was difficult to understand the reasoning behind why the Government sought to justify its surveillance of a 94-year-old peaceful protester and the judgment was “clear” police should have deleted the entries a “long, long time ago”.

The ruling served as a “timely reminder” of the importance of the convention in the wake of an “ever encroaching state” and proposals to review human rights laws, he added.

Rebecca Hilsenrath, chief executive at the Equality and Human Rights Commission, which supported Mr Catt’s case, said: “If you express a view in a legal and peaceful way, you shouldn’t end up as a criminal on police records.

“If we want a healthy democracy then we need to ensure that everyone has the right to participate fully in political life.

“We made clear in our evidence to the court that the National Domestic Extremism Database does not sufficiently protect individuals’ personal information and risks having a chilling effect on legitimate political protests.

“We welcome today’s judgment which upholds the importance of free speech and the right to privacy.”

The Metropolitan Police is yet to confirm whether Mr Catt’s data will be removed from the database as a result of the ruling and has not yet responded to requests for a comment.

But a counter-terrorism policing spokesman from the National Police Chiefs’ Council said it will “carefully consider” the court’s decision and the “implications for wider law enforcement/policing”.

The Home Office said it is considering the judgment.

Downing Street, the Ministry of Justice and Sussex Police have also been contacted for comment.