The mother of a terrorist killed by police after going on a stabbing rampage in south London described instantly “knowing” her son was responsible when she heard about the attack, shortly after they last spoke.

Haleema Khan said her son Sudesh Amman signed off their phone conversation with “Bye bye, I love you mummy” before going on to steal a kitchen knife from a shop and stabbing two unwitting members of the public on a Sunday afternoon in Streatham in February 2020.

He was shot dead by armed police within 62 seconds of launching his attack, in which both his victims survived.

Khan told the inquest into Amman’s death she had “no idea” her son was going to strike.

Speaking through a Tamil interpreter, Khan said she was on the phone to her husband on 2 February when an alert came through from a news website about the Streatham incident.

“I was frightened,” she said. “Then I noticed the jacket and the shoes on the news, that was given from me to him.”

In her witness statement, she said: “I saw that someone was shot dead in Streatham at 2pm.

“I knew it was Sudesh. I saw on a website that the dead man was wearing [his brother’s] jacket and his shoes.

“I then called probation as I wanted to tell them the jacket and shoes were Sudesh’s.

“I called my husband and told him. We were both then calling Sudesh for a long time.”

She told Jonathan Hough QC, counsel to the inquest, she then started to cry. “I was shocked,” she said. “I kept crying.

“All my children were running to me and asking why I was crying.”

Hough said: “Was there any explanation for what he did and what motivated him?”

Khan replied: “No, I didn’t think he was going to do these things and I had no idea.”

Khan told police she spoke to her son shortly after 1.30pm on the day of the attack, when he said he was on his way to buy some food.

The inquest had already heard that Amman left his probation hostel at 1.22pm on his way to Streatham High Road where he would carry out his attack while wearing a fake suicide device.

Recalling the conversation, she told police: “Sudesh said he loved me. He said, ‘Bye bye, I love you mummy.’ He said this before. That was the last time I spoke to Sudesh.”

The previous day, during a phone conversation about a recent family bereavement, Amman apparently told Khan: “Everybody [is] going to die one day.”

Amman was the oldest of six brothers and had been expelled from school for poor behaviour. He grew up in Coventry and Birmingham before moving to Harrow, north-west London.

The inquest previously heard how Amman was deemed to be “one of the most dangerous individuals” that police and MI5 teams had investigated, and that an officer feared an attack would be “when, not if” during discussions a fortnight ahead of his release.

He was automatically released from Belmarsh prison on 23 January 2020, part-way through a 40-month sentence for obtaining and disseminating terrorist materials.

This was despite police pleas to the Belmarsh governor to detain Amman for longer after intelligence suggested he maintained an extremist mindset, and wanted to carry out a knife attack in the future.

He was also said to have associated in jail with a number of extremists, including Hashem Abedi, who conspired with his brother Salman over the 2017 Manchester Arena suicide bomb attack, and previously expressed regret he had not been involved in the murder of Fusilier Lee Rigby outside Woolwich Barracks in 2013.

He also confided in others that he wanted to kill the Queen, the inquest heard.

Amman, who is of Sri Lankan descent, spent 10 days living in a bail hostel in Streatham, during which time undercover police teams monitoring him remarked at his “concerning” behaviour.

Amman was seen by covert police buying four bottles of Irn-Bru, kitchen foil and parcel tape from Poundland on 31 January, items which were used to make the “crude” fake suicide belt.

But they said there was not enough evidence to arrest him and feared searching his room would blow their cover.

The inquest continues.