A volunteer for the London Olympics arranged to buy a deadly dose of poison to murder her mother over Christmas in a Breaking Bad-inspired murder plot, a court has heard.

Kuntal Patel allegedly tried to kill her magistrate mother Meena by lacing her drink with abrin last December after she "forbade" the 37-year-old to marry her boyfriend, Niraj Kakad.

But the graphic designer was left devastated when the poison, which she bought from an American on the "dark web", failed to take effect and her mother survived, jurors heard.

She tried to buy more poison, this time a potent dose of abrin and ricin after seeing the drug used on the TV series, London's Southwark Crown Court was told.

In a series of emails through the illicit Black Market Reloaded, she begged poison dealer Jesse Korff to send her a dose to finish her mother off, the jury was told. An email sent on December 20 laments the fact the dose failed.

The court heard that, under the user name Headgear, Patel wrote to Korff, who was known as Snowman: "Something has definitely gone wrong somewhere because it is now Saturday morning and everything is normal.

"Yes, target definitely drank all of it. I made sure I watched her drink it all."

The email went on: "I need this to work more than trying to scam money from you. I can't be with the man I love because my mother does not like him.

"She is a very sad, bitter and lonely old woman and has been physically mean to me and my sister. I can only be with him if she is out of the way."

The email said she needed the deadly concoction to be "tasteless and untraceable".

It added: "I don't want her to end up with her stomach shredded and exploded and the doctors getting suspicious and telling police.

"Now having explained what I need, you can use your chemical knowledge to make it. Abrin/ricin seems the best way.

"Please, please know that I don't want to get caught and put in jail. I still have my future to live with the man I love, that's the only reason I'm doing this."

Over the next week she swapped a string of emails with Korff pleading with him to send the poison as soon as possible, the court was told.

At the same time, Patel sent Mr Kakad text messages telling him of her undying love for him.

On Christmas Day she wrote: "Merry Christmas, I wish I was with you. Love you and miss you. X. All I know is I don't want anyone else but you. It breaks my heart that my own mother doesn't care."

She added: "Good Christmas? Yeah right. We were meant to be getting married."

When Mr Kakad texted her back asking what presents she got for Christmas, she wrote: "Santa brought me misery."

Over the next few days she emailed Korff asking him to send the dose by express delivery and seeking assurances that this time the poison would work, the court heard.

A message on December 29 said: "I hope this new batch does work because I'm putting my trust in you."

On New Year's Eve she told the poison seller, who she nicknamed Heisenberg after Breaking Bad's drug-dealing lead character, that she needed the dose to work, the jury was told.

The email said her mother was "really psycho and I'm tired with her. Thanks and Happy New Year".

Korff, who made his poisons in a lab at his home, tried to reassure Patel that he was not scamming her and had sent her real poison.

He said it had "worked" for his other customers but agreed to sell her another dose.

But the FBI had been watching the exchanges and alerted British counter terrorism police before the next batch arrived.

Officers raided Patel's home in Plaistow, east London, on January 26 and arrested her.

Patel denies trying to murder her mother, who sits on the bench at Thames Magistrates' Court, and acquiring a biological agent or toxin.

She has pleaded guilty to two counts of attempting to acquire a biological agent or toxin last December.