The Liverpool bomber began making “relevant purchases” for his attack in April, counter-terror police have said.

Emad Al Swealmeen died in an explosion outside Liverpool Women’s Hospital in a taxi shortly before 11am on Remembrance Sunday.

Assistant Chief Constable Russ Jackson, head of Counter Terrorism Policing North West, said “a complex picture” was “emerging over the purchases of the component parts of the device”.

“We know that Al Swealmeen rented the property from April this year, and we believe relevant purchases have been made at least since that time,” he said a statement.

“We have now traced a next of kin for Al Swealmeen who has informed us that he was born in Iraq.

“Our enquiries have found that Al Swealmeen has had episodes of mental illness, this will form part of the investigation and will take some time to fully understand.”

Mr Jackson said a post-mortem examination had confirmed the cause of death as “injuries sustained from the fire and explosion”.

He also appealed for people who knew Al Swealmeen – especially during this year – to come forward, but said police currently “are not finding any link to others in the Merseyside area of concern”.

It comes after the home secretary said the attacker was able to exploit Britain’s “dysfunctional” asylum system to remain in the country.

Priti Patel said the system was a “complete merry-go-round” with a “whole industry” devoted to defending the rights of individuals intent on causing harm.

Al Swealmeen, 32, is understood to have arrived in the UK from the Middle East in 2014 and had an application for asylum rejected the following year, but was still in the country.

Ms Patel told reporters: “These people have come to our country and abused British values, abused the values of the fabric of our country and our society.

“And as a result of that, there’s a whole industry that thinks it’s right to defend these individuals that cause the most appalling crimes against British citizens, devastating their lives, blighting communities – and that is completely wrong.”

Al Swealmeen converted from Islam to Christianity and was not thought to have been known to MI5.

There have been reports of growing concern within the Home Office at the role of the Church of England in converting asylum seekers.