Martin Shkreli, a US pharmaceutical executive and hedge fund manager who gained notoriety for raising the price of a life-saving drug, has been sentenced to seven years in prison for defrauding investors.

Shkreli was convicted on Friday of misleading investors who put their money into two failed hedge funds he managed.

Prosecutors said Shkreli manipulated wealthy investors and deserved 15 years in prison.

His defence lawyer said he deserved a sentence of 18 months or less because the investors' funds were returned and they received stock in Shkreli's drug company.

Shkreli, who is known for bravado, struck a conciliatory tone at his sentencing.

"I am terribly sorry I lost your trust," he told investors. "You deserve far better."

Shkreli gained the nickname "Pharma Bro" after he raised the price of Daraprim, a cheap drug used to treat HIV, from roughly $13 to $750 a pill in 2015.

Throughout the criminal trial, Shkreli continued to engage in controversial behaviour.

He offered a $5,000 bounty to anyone who could secure a lock of former US presidential candidate Hillary Clinton's hair.

He was also kicked off Twitter for harassing a female journalist in early 2017.

Benjamin Brafman, the defence lawyer, had attempted to soften Shkreli's Pharma Bro's image.

One such attempt involved testimony about a cat Shkreli adopted and often appeared in his social media.

The cat is named "Trashy".

On top of his sentence, Shkreli was forced to forfeit more than $7.3m in accounts and assets and fined $75,000.