A five-year-old sat shyly in her metal hospital bed as her mother described what had brought her to Panzi hospital in the city of Bukavu, in the far east of the Democratic Republic of the Congo. A couple of beds down lay a tiny six-year-old girl, and further along sat a speck of a three-year-old in a fuchsia hoodie. This smallest girl had been brought in the previous night and had a painful fistula from gang rape.

In each case, what had been done to the girls is remarkably similar. Each was abducted at night from a wooden shack in their impoverished village, called Kavumu, about an hour-and-a-half drive from the hospital over the mudscape that is DRC in the rainy season. Each was then gang-raped and left in a nearby government-owned field overgrown with stalks of corn, sorghum and dried-out cassava; the area is used as a kind of subsistence farm by former rebel soldiers. A walk through the meadow is a tour of one spot after another in which little girls have been found bleeding and unable to move in the dead of night.

How this place became a repository of children destroyed has been a mystery for three years – since June 2013, when the rapes began. Girls began disappearing from their houses during the night while, mysteriously, their families remained asleep.

Parents assert that they’ve been drugged by a kind of “magic powder” sprinkled over their houses during the attacks. Men in groups of two, three or four have raped as many as 50 children, aged 18 months to 11 years old. At least two have died from their injuries. These girls are extremely young and malnourished, and therefore smaller than normal. Their injuries have been so extensive that one of the experienced doctors at Panzi, a hospital famous for treating the legions of women raped in DRC, told me that they had made her faint.

This is not your average “war rape”. These are terrifying, targeted, individual attacks against the country’s smallest children being perpetrated by what appears to be a powerful man and his minions, who believe – as do local Mai-Mai militia fighters – that the virgin blood of girls will fortify them for battle. The Guardian cannot name the man for legal reasons.

For many months the government has considered this man to be its main suspect – and even knows the names of men believed to be working under him. Yet it still has not moved to arrest him.

Since I left Kavumu in January, four more girls have been abducted and raped – one as recently as 3 June – according to sources close to the cases. I have spent the months attempting to understand the delays in arresting this man and his underlings, to no avail. I’ve been told everything from “The local prosecutor is too busy” to “Paperwork is still being transferred between offices.” Rumours that arrest warrants have been issued turn into rumours that they haven’t.

In addition, the government has identified a key suspect in the creation of the so-called magic powder, which, it turns out, may be a kind of anaesthetic made from local plants. There has been no attempt to arrest this man either. In the meantime the UN peacekeeping organisation Monusco has occasionally stepped up its night-time patrols in Kavumu, but apparently not enough to stop the abductions.

When I first wrote about these attacks for Foreign Policy magazine more than a year ago, the government in Kinshasa jumped into action, announcing it would launch a “national investigation”. While it did call an investigator to Kinshasa, ordering him to solve the crimes, the government offered no money or other support to make this happen (and has since touted arrests of men sources say have nothing to do with the rapes). Local corruption and incompetence – and, it finally seems, something more malevolent – may be at work. The man identified as the ringleader of the group – which allegedly includes government authorities – may have tentacles reaching all the way to Kinshasa.

The investigation of the Kavumu cases was for a long time piecemeal and chaotic. But at the end of 2014 a taskforce made up of Monusco, other UN offices, Panzi hospital and a few NGOs made the cases a priority, calling them a “crime against humanity” and putting pressure on Kinshasa. Those trying to do good in this situation have, however, been up against a barely functional legal system and corruption. The father of one victim, a man I’ll call Daniel, told me he was arrested and held for 24 hours the night he went to report his daughter’s rape. He was told to pay a bribe of $100 but talked his jailers down to $20 and was released.

For too long no one in the government 900 miles away in Kinshasa seemed to know or care what was going on in Kavumu. But to say the government is no longer aware of what is being done to the most vulnerable people in their country – and most likely by whom – is untrue.

A nine-year-old girl I’ll call Claudine is the older of two sisters abducted on 21 August 2014. A tall stick of a child wearing a threadbare, greying shirt, she said the men who raped her wore black masks and robe-like coats. She told me she still felt the terror of being left alone in the field when the men were done with her. When I asked how many of them had touched her, she said: “Too many.”

She looked down and whispered what she wants the world to hear: “Tell how we were taken from our houses without knowing,” she asked. “And how we were destroyed.”