A sex attack on a heavily-pregnant woman after raiders threatened to shoot both her and her boyfriend will be featured on BBC's Crimewatch tonight.
The 33-year-old woman was watching TV with her partner when the balaclava-clad trio were spotted outside the the property in Finsbury, north London, and forced their way inside.
While the boyfriend was threatened and hit with a gun, the seven-months-pregnant victim was taken upstairs by one of the attackers and forced to perform a sex act.
He threatened to shoot her and her boyfriend, 39, if she did not do as he said, Scotland Yard said.
A £20,000 reward is being offered for help in catching the men, who also stole the couple's grey Audi TT and other items including cash and a laptop.
A reconstruction of the incident - which took place on May 14 last year - will also be shown tonight.
Detective Inspector Robert Pack, the investigating officer, said he hoped "allegiances had changed" over the past 14 months as he appealed for information.
He said: "Every rape is a very serious crime but what makes this all the more shocking was that the victim was so clearly heavily pregnant.
"Concerns for the unborn baby can only have exacerbated what was already an emotionally and physically traumatic experience."
He added: "Allegiances may have changed over the last 14 months and we would urge anyone with information to contact us.
"There is a reward on offer of up to £20,000 and I hope there are people out there who are prepared to do the right thing and tell us what they know.
"Do you know the men who did this? Do you remember hearing anyone boasting about stealing an Audi TT around this time? We would like to hear from you."
The suspect who carried out the sexual assault is described as black, 6ft, aged 18 to 25 and stocky. He wore a black balaclava, black jacket, black tracksuit bottoms and black shoes.
A second man was black or Asian, 5ft 6ins and about 18. He wore light grey tracksuit bottoms, black trainers and a zip-up jacket with red sleeves.
The third suspect, who had the gun was black, 5ft 10ins, and aged between 18 and 22. He was wearing burgundy tracksuit bottoms.
* The Crimewatch episode will be broadcast at 9pm.