The father of five-year-old brain tumour patient Ashya King has claimed he was harassed by police and “treated like a criminal” when he tried to return to the UK.

A YouTube video published on Monday shows Brett King and his son Naveed being stopped by a police officer as they attempt to walk through UK border control at Gatwick airport in west Sussex last Saturday.

King said his and Naveed’s passports were taken away and police were called when they tried to re-enter the UK.

He is then shown in the video telling a police officer: “How would you feel coming back to your own country to be treated like a criminal? What have I done except help my son? Show me the computer and I’ll come with you. I’m walking now, you can arrest me if you like.”

It is the first time King has attempted to return to the UK since August when Ashya was taken from hospital in Southampton without consent.

The five-year-old, who required brain tumour treatment, was taken to Spain by his parents where they were arrested. They were later released and allowed to take Ashya to Prague for proton beam treatment, which he completed last month.

In the three-minute video, published on Naveed’s account, King is shown in the UK border control area of Gatwick airport.

Addressing the camera, he says: “I’m here at Gatwick airport, I handed my passport in, the man looked at his computer, asked me to come to this holding booth and took my passport away as well as my son Naveed’s passport away.

“Now behind me is the police making phone calls and that sort of thing when I was told that there would be no problem if I come back to England, but already my first attempt to come back to England or a time when I’d like to come back to England, there’s been problems. We’ll see what will happen in a few minutes.”

He then gets up and asks a police officer to see what is on a computer screen, presumably that of the UK border agency official, before being told to calm down.

King told the police officer: “I’m not going to follow you. You’ll have to arrest me. I don’t like being treated like a criminal in front of the public.”

“I’m not gonna arrest you,” says the police officer, before King is filmed walking through border control unapprehended. Two police officers appear to follow King up the escalators into the arrivals lounge, where they instruct the person with the camera – thought to be Naveed – to stop filming.

In a comment posted later underneath the video, Naveed said: “[The police officer] wanted to take Brett in for questioning. After we found out he wasn’t under arrest that’s when we got up and walked, and that’s when we also wanted to see WHY he was stopped and to see what information they have on Brett in their computer system.”

A Sussex police spokesman told the Guardian: “Two uniformed constables who were on routine patrol in the airside area were called by UK Border Force to advise on an issue relating to a passport held by an arriving passenger in Immigration Arrivals on Saturday 29 November.

“When the officers arrived they quickly confirmed to Borders staff that police had no interest in the matter. One of the officers spoke briefly to him and he walked through to landside.

“The officers made it clear to the man that they did not intend to arrest him. We have received no complaint about the actions of the police.”