The British Home Office is returning a severely epileptic boy's cannabis oil medication after confiscating it, a family spokesman has said.

Charlotte Caldwell tried to bring the medication into Heathrow Airport to treat her 12-year-old son Billy, but it was removed by border officials.

A family spokesman said today: "The medication that she brought into the country and was confiscated, this medication is on the way to the hospital." 

Billy, who is from Castlederg in Co Tyrone, was admitted to Chelsea and Westminster Hospital in London yesterday after his seizures intensified.

Home Secretary Sajid Javid said: "This morning, I've used an exceptional power as Home Secretary to urgently issue a licence to allow Billy Caldwell to be treated with cannabis oil.

"This is a very complex situation, but our immediate priority is making sure Billy receives the most effective treatment possible in a safe way.

"We have been in close contact with Billy's medical team overnight and my decision is based on the advice of senior clinicians who have made clear this is a medical emergency.

"The Policing Minister met with the family on Monday and since then has been working to reach an urgent solution."

Speaking outside the hospital earlier this morning, Billy's mother Charlotte said: "Unfortunately, Billy had two more seizures overnight which has pushed him more into a crisis situation."

She added: "The Home Office, myself and my team have been working extremely hard throughout the night to make this happen, which is truly amazing, but there can only be one conclusion here: that my beautiful sweet little boy, who has a life-threatening form of epilepsy and one seizure can kill him, he needs his medicine back today."

"I am hoping the common sense will prevail."

Doctors said it was too dangerous to treat Billy with "rescue meds" at home and he can now be treated only with hospital-administered medicine.

Ms Caldwell credits the cannabis oil with keeping her sick son's seizures at bay, saying he was seizure-free for more than 300 days while on the medication.

She added doctors in Canada and Northern Ireland familiar with Billy's case said the situation was life-threatening.

Billy started the treatment in 2016 in the US, where medical marijuana is legal.

He became the first person in the UK to receive a prescription after his local GP in Northern Ireland, Brendan O'Hare, began writing scripts.

However, there is no record of a health service prescription being dispensed.

Dr O'Hare was summoned to a meeting with Home Office officials recently and told to stop.

Ms Caldwell made the trip to Toronto and back with her sick son to get a six-month supply to treat up to 100 seizures a day.