The leader of far-right political group Britain First has been found guilty of an offence under the Terrorism Act after refusing to give police access to his mobile phone on his return from a political trip to Russia.

Paul Golding, 38, was stopped at Heathrow Airport on October 23 last year on his way back from Moscow by officers from the Metropolitan Police.

He refused to give them the pin for an iPhone and Apple computer and was later charged with wilfully refusing to comply with a duty under Schedule 7 of the Terrorism Act.

Golding denied the charge but was found guilty of the offence following a trial at Westminster Magistrates’ Court in London on Wednesday.

Chief magistrate Emma Arbuthnot ruled there was “no doubt” that Golding had failed to comply with requests for information, despite his obligations being explained to him and being warned “over and over” that if he did not he risked arrest.

She handed Golding a conditional discharge for nine months and ordered him to pay a £21 surcharge and £750 in costs.

Giving evidence earlier, Pc Rory O’Connor, a borders officer with the Met who questioned Golding, told the court that Schedule 7 enables accredited officers to “speak to people in order to make a determination of whether they are or have been concerned in the commission, preparation or instigation of acts of terrorism”.

The officer explained that it also permitted police to interrogate, search and detain anyone for up to six hours at UK ports.

He said he had cause to examine Golding under the legislation and recalled him being initially “agitated” and “clearly angry” at being stopped, with him shouting at officers.

Prosecutor Samuel Main said that for nearly three hours Golding was questioned about his activities in Russia after flying out with two others on October 20.

The court heard that Golding said he was on a “purely political trip” after establishing friendships in Russia during an international congress on an earlier date.

He told officers that he had returned to the country under the invitation of the Liberal Democratic Party of Russia (LDPR), which he described as a “right wing, conservative, patriotic group” who were not “extreme”.

Golding said they were a “political party not a mob” and “if they incited violence then Britain First wouldn’t touch them with a barge pole”.

He said he had not met any representative of the Russian government, the court heard.

Golding, of Hodder Bank, Stockport, appeared in the dock wearing a grey suit, white shirt and red tie, and spoke only to confirm his name, date of birth, address and nationality.

English Defence League founder Tommy Robinson, whose real name is Stephen Yaxley-Lennon, watched the proceedings in the court’s socially distanced public gallery.

Over the course of his three-day trip, Golding gave interviews to the media, met members of the LDPR and visited the Russian parliament, Main said.

He also visited Moscow’s Red Square and laid a wreath at the tomb of the unknown soldier.

Golding was quizzed on the LDPR’s policies which he said covered the issues of terrorism, Islamic extremism, immigration and family values.

He described Britain First as a “patriotic, right-wing, conservative” group who considered themselves as “loyalist”.

In clips of an audio recording of the interview played in court, Golding said the request for his pin codes was “wildly inappropriate”, “completely unjustified”, represented an “abuse of police powers” and was a “political witch hunt”.

Main said he told officers they “hadn’t asked him about terrorism or criminality and he was simply a politician”.

Golding added: “I don’t think think you have any grounds to suspect me of terrorism in any way shape or form”.

Representing Golding, Abigail Bright said Britain First had never been a banned organisation.

She said Golding had been “calm, compliant and respectful” during questioning under what she claimed was a “predetermined operation”.

Bright said he was “tired” and had not wilfully disobeyed a lawful instruction and that evidence from officers left the court “none too wiser” as to whether they had “screened against” Schedule 7 being used “in an arbitrary way”.

She highlighted that she had put to Pc O’Connor that as a political leader there was a “real possibility” Golding’s devices held sensitive information, for example membership lists.

As a politician, she said he was “entitled to expect enhanced protection for his rights of speech, assembly, association”.

Main said that at “no point” had Golding mentioned there being “sensitive material” on his devices, which might have offered him some protection.

Britain First was deregistered as a political party in November 2017.