For four days this week, her chair has been empty and, in a painful series of conversations, her colleagues have been sharing glimpses she gave them of the pain hidden beneath her warmth.

It is in the particularly horrific death of Aulakh that the secrets of her life are emerging. Police believe what spilled out on to the street in Greenford, west London, on Monday evening was the violent culmination of something hidden in Aulakh’s recent past.

Senior sources believe the 28-year-old was held down by more than one assailant and struck repeatedly with either a sabre or a machete as she went to pick up her two sons from their childminder. Aulakh was just 100 metres away from her young children, on a quiet street, where residents fear burglary or car crime, not the sort of scene they experienced that night.

In the frenzied assault, Aulakh was struck repeatedly around the head with the sabre-like weapon. She fought for her life, sustaining a serious wound to her right hand which severed it from her arm, leading to speculation that it was cut off deliberately in some sort of religious ritual. The suggestion is a distraction, sources say. The wound was a classic defence injury against an assault with a long, extremely sharp weapon.

The choice of location was deliberate, the police believe. They say it was no random attack, but a planned assault by more than one assailant on a woman whose regular routine was known.

The nearness to her children is, again, no coincidence. “We are not talking about a stranger attacker here who she does not know. It is complicated but what you are looking at is a fairly closed group of people,” the police said. It is only now as people talk about her murder that some friends are sharing conversations in which Aulakh suggested she was frightened and felt harassed but did not specify who was causing her sense of feeling terrorised.

Avtar Lit, her boss at the radio station, said: “She was a private person. What is emerging now is that Geeta did share with some of her female colleagues that she felt frightened and harassed, but she didn’t reveal a great deal, and little bits of what she said are coming out now.”

The police are studying CCTV footage from Southall station and the bus to see when she might have been followed by her killers. In their investigation, detectives are probing every aspect of Aulakh’s past, attempting to unpick the secrets she guarded so closely. They say they have ruled out a so-called honour killing as a motive but admit that the circle they are investigating is one close to Aulakh herself.