A French woman who has an EU settlement application under way was detained and held by Home Office officials at a London airport for more than eight hours.

Tessa Stines has been living in the UK for the past year and volunteering for a charity, while making trips back to France during that period.

On returning last month through Gatwick, Stines, 23, was detained by Border Force officials in a holding room at the airport, alongside an Afghan woman and a Spanish woman.

“We were all in a very stressed state while we were being held in that room at the airport,” said Stines. “I took the contact details for the Spanish woman and saw on her Instagram later that she had been removed from the UK.”

Stines was detained despite a rule change announced by the Home Office in May when Border Force officials were instructed not to detain EU citizens. They were told to instead issue immigration bail after heavy criticism following Guardian reports of multiple cases of women and men being held in removal centres earlier this year.

The Guardian knows of another individual with dual nationality from Britain and an EU member state who was detained last week at Manchester airport and mistakenly told she needed to apply for EU settled status within 28 days even though she has UK citizenship.

Unlike some of the previously reported cases, Stines was detained while her application for pre-settled status was still under way. Officials later admitted the decision to detain her was incorrect although no apology has been issued.

When Stines was released she was given a letter from Home Office officials dated 23 August that said they were not satisfied she “qualified for permission to enter” and had refused her leave to enter the UK.

After the Guardian contacted the Home Office about the case Stines received a further letter reversing the decision to refuse her entry. The letter from Gatwick Border Casework dated 11 September 2021 states that Stines’s application for EU pre-settled status was refused on 20 August.

She had previously been sent two emails by Home Office caseworkers asking for further documentation to support her application but had not seen the emails because they had gone into her spam folder. She is currently gathering the further evidence requested by the Home Office.

The letter states that when she was detained at the airport she was still within the timeframe to appeal against the refusal of her application. “In view of this I have concluded that the decision to refuse you entry to the UK should be withdrawn.,” it said.

“The whole thing has made me feel really stressed,” said Stines. “While I was detained the officers took photos of the pages of my personal diary. I have been triple checked, my fingerprints have been taken and my notebooks have been read. I would say this is not really ‘friendly’ behaviour for neighbours.”

A Home Office spokesperson said: “An individual who was not resident by 31st December 2020 who submits an application to the EUSS [EU settlement scheme] will not automatically have a right of entry until their application is granted, and those coming to work or study must prove they meet our entry requirements.”