Solving the acid attack case was so complex it took murder investigators to bring it to court.

Det Ch Insp Dave Whellams said his team normally worked on murder investigations but even he admitted bringing 21-year-old Mary Konye to justice was “difficult”.

In a statement to reporters after a jury today found Konye guilty of throwing acid over her childhood friend Naomi Oni, he also commended the victim for her bravery.

“It was difficult. Mary had disguised herself. She thought it through. She used travel documents that weren’t hers,” said Det Ch Insp Whellams.

He said the defence case, in which Konye claimed she and Ms Oni had together planned a fake attack in the hope of earning fame and fortune from media attention, was “completely implausible”.

He added: “They can’t really tell me what the argument [that provoked the attack] is. It’s small, it’s fashion, it’s boyfriends. It’s all arguments that everybody has.

“But it’s hit such a raw nerve with Mary Konye she has planned this [attack].”

Konye, of Throckmorton Road, Canning Town, attacked Ms Oni with concentrated acid along Lodge Avenue, Dagenham, in the early hours of the morning on December 30, 2012.

Ms Oni has been left with severe facial scarring. She has had to undergone numerous surgical operations, including skin grafts, and is likely to require many more.

Det Ch Insp Whellams said Ms Oni, also 21, was “a very brave woman and one I have a great deal of sympathy for”.

He added: “Naomi at the moment is in shock. Obviously there will be a lot of relief and anger.

“This friend after the attack was phoning and texting her when all the time she was the one that was behind it.

“She probably feels a lot of emotions at the moment and is going to take a while to settle down.”