The family of a British teenager murdered in 2014 have received taunting messages on Snapchat purporting to be from his killer.

UK member of Parliament Chris Philp raised the issue with Prime Minister Theresa May, saying Snapchat was not handing over vital data about the messages to police.

Two senior Snap executives will now be grilled by a parliamentary committee about the case. Chair Damian Collins said it was an "egregious example" of a company failing in its responsibilities.

Snap said it understood how upsetting the issue was for the family and it has terminated the account of the user who sent the messages.

Snap executives are going to be grilled by a UK parliamentary committee after the family of a murdered 14-year old received taunting messages purporting to be from his killer.

Breck Bednar was murdered in 2014. Lewis Daynes, 18, was convicted of the killing and sentenced to life in prison, which he is currently serving.

Five years later, Breck's sister Chloe started receiving taunting Snapchat messages, purported to be from Daynes, graphically recounting Breck's murder.

Breck's family contacted their local member of parliament Chris Philp about the messages.

Philp raised the issue with Prime Minister Theresa May on Wednesday, saying that Snapchat has not handed over vital data to British police about who was behind the messages. May said it was a matter of "great concern" and that the government is "urgently looking into this issue."

Theresa May. Sean Gallup/Getty Images

Philp also published a scathing attack on Snapchat in the Times newspaper, accusing Snap of "hiding behind their terms and conditions" and referring UK police to a process mutual legal assistance treaty, which is required to obtain data from a US-based company. Philp wrote the process takes 10 months on average.

He told Business Insider that it's not yet clear, with Daynes behind bars, whether he's the one sending the messages.

"It's not clear if it's the perpetrator who's somehow got hold of a device in prison, or [has] borrowed somebody else's device in prison, or if it's an associate of the perpetrator, or indeed it could be someone completely different," Philp said. Snapchat has data about which device the messages were sent from, but is not handing over the information, he added.

Philp said this isn't the first time the family have received taunting Snapchat messages. "They first actually got in touch with me about bad messages like two years ago... and then it started happening again a couple of months ago," he said.

Snap founder Evan Spiegel. Getty

Now, two top UK Snap executives — EMEA director of public policy Stephen Collins and its EMEA director of creative strategy Will Scougal — have been called to give evidence to the parliamentary Digital, Culture, Media and Sport Committee later this month.

"The unique format of Snapchat presents a number of important challenges that I believe that the company should be addressing," chair of the committee, Damian Collins, said in a statement.

"I was particularly disappointed to hear of Snapchat's inadequate response to police inquiries regarding approaches that have been made to the family of Breck Bednar, who was murdered in the most abhorrent circumstances. Social media companies have a responsibility to cooperate with law enforcement agencies to protect their users, and this perhaps the most egregious example of a company failing in that responsibility. We will be raising this tragic case with the company as part of our evidence session with them."

In a statement to Business Insider, a Snap spokeswoman said:

"We've put a lot of thought and effort into making Snapchat a place that prioritises close friends and privacy and we make it very difficult for anyone you don't know to contact you. We understand how upsetting this situation is for the Bednar family. We have provided advice on restoring privacy settings and we have also terminated the user account.

"We value the strong cooperation that we have with our law enforcement partners in the UK and we work hard to be as helpful as we can. We welcome any efforts that help to speed up the Mutual Legal Assistance Treaty (MLAT) process whilst allowing for appropriate judicial oversight and avoiding conflicts of law."