Image copyright AFP Image caption Mr Sirisena said Yvonne Jonsson's murder had been an "act of impatience"

Sri Lanka's outgoing president has caused outrage by pardoning a death row prisoner who murdered a Swedish teenager in 2005.

Jude Jayamaha, from a wealthy, high-profile family, walked free from prison following President Maithripala Sirisena's highly unusual decision.

The victim's sister, Caroline Jonsson, said the killer had shown no remorse. Sri Lankans criticised the move online.

Mr Sirisena is not standing in next Saturday's presidential election.

He failed to get support from his own party to contest the poll.

President Sirisena announced last month he was considering a request to grant Jayamaha a pardon, saying he had behaved well in prison and had been jailed aged 19 "over an incident of impatience".

Victim Yvonne Jonsson, a dual national whose mother was Sri Lankan, was beaten to death in the stairwell of the apartment block where her family was living in the capital Colombo in 2005 after an earlier argument with Jayamaha.

During the trial, the court heard that her skull had been fractured into 64 pieces.

Jayamaha was initially given 12 years in prison. His subsequent appeal against his jail term was rejected and he was sentenced to death instead, a sentence upheld by the Supreme Court in 2014.

Last month Yvonne Jonsson's sister Caroline said the family had been distressed to learn that Mr Sirisena was considering a pardon.

"We've worked hard to rebuild our lives and here we are, going into 15 years, still fighting for justice," she wrote in a Facebook post.

"Unfortunately, we now have to prepare ourselves for the worst possible outcome, the pardon of my sister's murderer."

She dismissed Mr Sirisena's characterisation of her sister's murder, saying it was a premeditated act and he had waited for her outside the family's apartment before attacking her.

Many Sri Lankans took to social media to condemn the pardon.