A cocaine-addicted former nightclub bouncer has been jailed for at least 35 years for the rape and murder of heavily pregnant teenager Nikitta Grender.

Loner Carl Whant appeared to yawn as he was found guilty by a jury of raping the 19-year-old before stabbing her to death and setting her body on fire.

Miss Grender's family made an emotional plea for Whant, 27, to tell them the truth after a judge said the full facts of what happened in the early hours of February 5 2011 may never be known.

Days after murdering Miss Grender, who was the girlfriend of his best friend and cousin Ryan Mayes, the tattooed window salesman visited her grieving parents while crying crocodile tears and clutching a bunch of flowers.

Miss Grender's uncle Michael Brunnock said: "Nikitta was so young and beautiful. Together with Ryan, they were to become a very proud set of parents. This has been ripped from them by Carl Whant, who has never had the decency to tell us the truth. For Nikitta's mum and dad to see their grandchild for the first time in a mortuary was the most heartbreaking thing they have ever had to do."

Whant stabbed eight-and-a-half months pregnant Miss Grender to death at her home in Broadmead Park, Lliswerry, Newport, South Wales, after he had left a house party he had been at with her boyfriend in the early hours of February 5 last year.

She and Mr Mayes were said to be excited at the prospect of becoming parents - and had already decided to call their daughter Kelsey May. After killing Miss Grender, Whant then set fire to her home - also risking the lives of a mother and baby who lived in the flat below.

During the trial, he claimed the reason why his semen had been found inside Miss Grender's body was because he had been invited by his cousin to have consensual sex with her.

The false allegations piled more pain on 17-year-old Mr Mayes - who not only had to contend with losing his child and girlfriend - but having his sex life cross-examined in public following a terrible betrayal by the man he once regarded as "a father figure".

In sentencing him to life with a minimum of 35 years, judge Mr Justice Griffith Williams told Whant: "You are a calculating, vain and devious individual and the explanation for these terrible crimes comes in part from your vanity."