By Thomas Fessy and Mark Doyle
BBC News, Mwenga
High in the mountains of South Kivu Province, eastern Democratic Republic of Congo, a Congolese miner caked in sweat and dust hacks at rock in search of precious minerals.
Some of his fellow miners in the region look for coltan, a mineral used in the manufacture of mobile phones. Others search for gold.
This man is using an iron stake and a simple shovel to dig for cassiterite, or raw tin.
Much of the final product from the efforts of cassiterite miners like him ends up as the microscopically-thin layer of tin which lines metal food and drink cans.
Tin does not corrode so it is safe for food packaging.
That is why there may be a tiny bit of DR Congo on your table or in your cupboard today.
Some of these tins may have started out in DR Congo
"We have to pay the rebels to work here," the digger we met said.
"They force us to give them cash or the equivalent in minerals," he added, standing on the edge of his three-meter deep pit.
The roof of the dangerous pit - more like a cave, really - was propped up by sawn tree trunks. But the hundreds of tonnes of rock they supported looked like they could collapse at any time.
Many of the mines like these in eastern DR Congo - in North and South Kivu provinces - are controlled by ethnic Hutu rebels from the Democratic Front for the Liberation of Rwanda (FDLR).
This group first arrived in DR Congo - under other names - in 1994 after Hutu military commanders and militiamen had masterminded the genocide of Rwandan Tutsis and moderate Hutus.
The FDLR still vows that it will return to power in Rwanda.
It says it doesn't want war and calls for a political dialogue with the Rwandan government (which the Tutsi-dominated elite in Kigali is most unlikely ever to agree to).
The FDLR says its weapons are just an insurance policy.
But for now, with the rebel group deeply implanted in the forests and mountains of DR Congo, those weapons are also used to extort taxes and minerals from local diggers and traders, reaping profits worth millions of dollars a year.
We drove from the provincial capital of South Kivu, Bukavu, towards the trading town of Mwenga.
Once hardly accessible by car - and therefore controlled by a variety of armed groups the central authorities could not reach - the dirt road has in the past two years been considerably improved by a Chinese company on contract to the Congolese government.
In remote villages, Congolese people have been living under the control of this foreign armed group for years.
After having made contact with the rebels by mobile phone, we met them after about an hour's trek through the bush from Mwenga.
The man sent to answer our questions was Colonel Job Rukondo. He declined when we asked if we could take his photo.
It is the Congolese administration which is in charge of the mines in this region. We mainly live off farming. We raise cattle and trade at local markets
Most of the armed men around him were in smart uniforms barely distinguishable from those worn by Congolese government forces.
This should not come as a surprise - for many years the FDLR were the allies of Kinshasa and worked closely together with the Congolese government army fighting forces loyal to Kigali.
In recent months, however, the relationship between the FDLR and the Congolese authorities has soured, at least in public, with the government of President Joseph Kabila saying the Rwandan rebels have now outstayed their welcome.
President Kabila even recently allowed the Rwandan army into North Kivu to track and chase the Hutu rebels.
The Rwandan army officially returned home a few weeks ago, though some of its close allies remain in position.
President Kabila had found it politically embarrassing to have a foreign army on Congolese soil - especially one which had, in the past, twice changed the government in Kinshasa.
But clearly the Rwandan government forces did not complete all the tasks they had set for themselves, because here was a Rwandan rebel officer ready to speak to the BBC, and still on Congolese soil with his men.
Colonel Rukondo was dressed in civilian clothes when we met.
His men, many shod in stout Wellington boots, touted automatic rifles and machine guns and formed a tight close protection perimeter around us.
We are like lambs facing wolves
Colonel Rukondo denied that his movement raised money through illegally taxing Congolese miners and traders.
"We are not involved in mining activities at all," he said. "I don't think I know of any mines around here.
"It is the Congolese administration which is in charge of the mines in this region. We mainly live off farming. We raise cattle and trade at local markets."
We left Colonel Job and walked further up the mountain in search of a mine we had been told about earlier.
The slope was steep and at times the pathway turned into a rushing stream.
The few Congolese villagers that we met on the way all affirmed that the Rwandan rebels controlled the mines in the area. They also said they were living in fear as the rebels often mistreated them.
The FDLR rebels continue to operate in eastern DR Congo
"We are like lambs facing wolves," one villager said.
"We feel in danger from these rebels all the time. The international community should really take on the issue, and make them return to Rwanda."
The Congolese army, supported logistically by the UN peacekeeping mission in Congo, has said it will soon carry out military operations in South Kivu similar to those conducted by the Rwandan army in North Kivu.
But the Congolese army may not have the necessary equipment and training to mount such a mission.
In Mwenga, local traders also told us that they had to pay the FDLR rebels to get in and out mine sites under their control.
They also had to pay a tax for each bag of minerals that they removed from these sites.
We followed the mineral trail from Mwenga to the city of Bukavu, where several large export companies have warehouses and offices.
We asked local business leader Basila Milabyo if it was true, as traders on the ground had told us, that the export houses knew exactly where the minerals they were purchasing came from - and, by implication, of course, that some of them colluded with the illegal activities of the FDLR.
"Well, even in areas controlled by these rebels, the diggers are Congolese", Mr Milabio said.
"We buy minerals from traders, so we can tell which market or company they're coming from - but we can't tell the exact mine".
Later, Mr Milabio strayed a little from the official line.
"Look", he said, in a rather tired and impatient way;
"What can we do to chase them? We suffer from their presence as well. They rape our women, and people are leaving the bush because of them, taking refuge in town. How can we get the weapons to fight them? We have none."
He refused to answer whether these sorts of abuses by the rebels might be stopped if the members of his business association stopped paying out money which might end up in the hands of the FDLR.
Many FDLR members insist that they were too young to have taken part in the genocide of 1994.
The Rwandan government has lists of people in the FDLR that it says took part in the mass killings. The allegations against some of them may well be true.
But its also true that an entire new generation of boys and girls has been raised by the Rwandan rebels inside Congo - and some of them barely know their homeland at all, let alone took part in the wars there.
Since arriving in Congo in 1994 the FDLR and its predecessor Hutu organisations have woven a web of complex relationships with their hosts.
Some of those relationships are military. Some are related to businesses - legal as well as illegal. Some of the relationships are personal.
The international community has encouraged the Congolese government to demonise the FDLR and say the rebels should return to Rwanda or else...
In reality, even if Congo had the military capacity to enforce its will, untying the relationships the FDLR has developed in Congo over the past decade and a half may take many years.