A father of two who is among dozens of Jamaicans to be removed from the UK on Wednesday morning was told by the Home Office that he can keep in touch with his British family via the internet.

Arthur Muir, 30, was on suicide watch at Dungavel detention centre before being moved to London, his wife, Sarah Jackson-Muir, told the Guardian. He is one of a number of people with seats on flight PVT070 on Wednesday, including many who have lived in the UK since they were children and have made their lives here.

The Home Office refuses to confirm the existence of the removal flight, the second to Jamaica since 2014. The Guardian has only been able to piece together details through migrants’ rights activists and relatives of those set to be on board.

Muir, who came to the UK aged 13, was previously deported from Britain after a teenage conviction for selling drugs, his wife said. The couple had tried to secure him British residency by marrying, then living together in Germany and Ireland before returning to the UK.

However, his new application to remain was rejected because Jackson-Muir, 29, does not earn the £18,600 required to be the sponsor on a spousal visa – a financial hurdle upheld by the supreme court last month.

Jackson-Muir said her husband had been held incommunicado in a police cell for five days having been picked up in Aberdeen after going on the run from immigration control. She was only able to discover his whereabouts after ringing around police stations and detention centres, she said.

“He wasn’t living with me anymore,” she said. “He couldn’t stay here because they kept coming here basically because they want to detain him.

“We were trying to get the money together to go back to Ireland to just live, but obviously we can’t go with £100 because this isn’t going to work – we need to be able to rent a place for sufficient time because we’re not going to survive otherwise.”

In documents sent to the family, seen by the Guardian, an official tells Muir: “You have put forward no reason to suggest that it would be unreasonable to expect your claimed partner and son to accompany you to Jamaica; however, should they choose not to it is considered you would be able to remain in contact with them via modern methods of communication ie telephone, internet or by written correspondence.”

Case workers at the Unity Centre, a Glasgow-based migrants’ rights group, have highlighted a number of cases of people who have lived in the UK for their entire adult lives who will be forced to leave behind British spouses and children to return to a country many have not seen since they were children.

Sophia, also Jamaican, who has been in Yarl’s Wood since October, is being deported on the same flight after a conviction for shoplifting 10 years ago that led to her losing her indefinite leave to remain.

According to a fundraising page set up to help her fight the deportation, she has been in the UK for more than 25 years and has three British children, the youngest of which is 13 and has sickle cell anaemia. She was told she could stay in touch with her children via Skype, the page says.

On Monday night, according to the Unity Centre, Brook House detention centre was put on lockdown when guards donned riot gear and attacked a Jamaican detainee who refused to leave his cell.

“The Unity Centre received several calls from distressed detainees who were coughing uncontrollably and had difficulties speaking, because the guards had opened the roof of the building and turned on the air conditioning at full blast,” the organisation said.

“Many detainees are concerned about their health, feeling ill from the open roof and are not confident in the notoriously inadequate health provisions inside detention. Making detainees ill is one tactic by the Home Office to make them weak and thus easier to subdue and remove.”