How we tracked down the Ukrainian poison seller

On a website where people openly discuss suicide, "the Ukraine supplier" was a name frequently discussed by members.

The mysterious trader was shipping a chemical commonly used for suicide around the world from Ukraine's capital. He has been linked to at least 130 UK deaths.

We traced his online store, as well as his email address and PayPal account, and managed to identify the man as Leonid Zakutenko.

In January 2022, we decided to make direct contact with Zakutenko, posing as an interested buyer on the pro-suicide forum.

He quickly messaged back and said he could supply the chemical. The forum advises users to take anti-vomiting drugs along with the chemical. We asked if he could also supply these and he confirmed that he could.

The BBC is not naming either the pro-suicide website or the chemical being sold.

Then, a month later, Russian tanks rolled over the border into Ukraine and the possibility of confronting him on his home soil seemed gone for good.

With war raging, we didn't think he would be able to carry on trading.

But we continued to catalogue the increasing number of deaths linked to the forum and met families whose loved ones had used the site to help end their lives.

If you've been affected by the issues in this story, help and support is available via the BBC Action Line

More than a year passed, but in May 2023, the same forum and chemical hit the headlines following the arrest of another man who was frequently mentioned by members.

Kenneth Law was arrested in Canada on suspicion of "counselling and aiding suicide" by distributing the dangerous product worldwide.

The former chef has since been charged with 14 counts of murder and linked to hundreds of deaths around the world.

It made us wonder if the Ukrainian was still in business and we set about tracking him down.

We made contact again, posing as a buyer. He boasted that he was now sending "five parcels a week" to the UK and could offer an express service.

For Zakutenko, it seemed, trade was good. Perhaps there was a gap in the market now that Kenneth Law was behind bars.

We decided to try again to confront him.

In January, we flew to Krakow, in Poland, and took the 12-hour car journey across the border to Kyiv, where we'd arranged to meet Zakutenko through a fixer who spoke Ukrainian.

We discovered that Zakutenko was an AirBnB "superhost" and planned to meet under the pretence that we were interested in a long-term lease of one of his apartment rentals.

Zakutenko had promised to show us around the apartment and we spent the long journey wondering whether he'd really turn up in person.

From Leeds to Kyiv

Our journey through war-torn Ukraine seemed a world away from the small front room in Leeds where the investigation started.

There, Catherine Adenekan and Melanie Saville introduced us to the online forum promoting suicide, and the real-life impact it was having.

The forum has tens of thousands of users, many of them young and vulnerable. Like Catherine's son, Joe, who took his own life in April 2020. In just three weeks, the 23 year-old used the forum to source a lethal chemical and learn how to use it.

Catherine still has her son's suicide note, tightly wrapped in a plastic police evidence bag. In it, he spells out how dangerous the forum had been for him.

"Please do your best in closing that website for anyone else," it reads.

She's been doing just that ever since, together with Joe's sister-in-law Melanie.

Together they have infiltrated the site, documented the numbers of deaths associated with it and identified people selling the chemical.

They have been lobbying their local MP and talking to the media in an effort to get the forum closed down. "Without that site, there wouldn't be a platform for people to sell poison," says Melanie.

The doorstep

When we finally got to Kyiv and called to confirm arrangements, our hearts sank. Zakutenko told our fixer he was out of town and that a cleaner would show us the place instead.

Was he really out of town? Or had he become suspicious? We'd heard stories of Ukrainian men of fighting age being stopped at roadblocks, drafted immediately into the army, and sent to the frontline. Perhaps Zakutenko was just trying to keep a low profile.

We went to his apartment, a high-rise Soviet-era block on the city's outskirts. There was no sign of him.

Within walking distance was a post office. A quick check with contacts in London indicated that this was the counter where he'd been dispatching poison - the tracking details on a previous test purchase proved it.

We messaged again, this time pretending to be a different UK buyer in urgent need of the chemical. He promised that he would send it within an hour if we paid for his "express" service. We did, hurriedly setting up a payment account and waiting outside his door as the minutes of that hour ticked by.

But Zakutenko didn't emerge.

We messaged again. He replied, assuring us that the parcel had been posted and sent a tracking number.

Leonid Zakutenko on the streets of Kyiv during surprise filming by the BBC

We convinced ourselves that he'd moved on and was now using a different post office. But the tracking number didn't work. So we waited, just in case.

Several long hours later a stocky man in a leather jacket and black beanie hat came out of the block, clutching a large black bag, ambling up the road toward the post office. It looked like the photographs we'd seen on Zakutenko's social media, but it was hard to be certain.

We followed the man inside and watched as he posted at least 15 parcels to different consignees around the world. As it was entered into the system, our tracking number suddenly appeared on the Ukrainian postal service website. It was Zakutenko. We had watched him dispatching the poison we had just ordered.

Outside we were ready to confront him.

But the city's air raid sirens suddenly came to life, piercing the silence.

We made a quick call to our safety adviser, to check if we had to take shelter. Thankfully they confirmed it was a false alarm and we continued to wait.

The sirens were still wailing as Zakutenko walked down the post office steps.

We asked him why he was sending poisonous chemicals to people who wanted to end their lives. The question was repeated in Ukrainian by our interpreter.

"That is a lie," he told us, before putting his hand over our camera and trying to walk away.

We persevered and asked what he had to say to the families of the dead. "I don't understand what you are talking about," he replied.

Over and over, he said he didn't understand our questions. But he'd been messaging us in perfect English just a few hours earlier.

We have alerted the authorities in both the UK and in Ukraine.

The forum, where details of those selling poison are widely shared, is still up.

The government says the new Online Safety Act gives Ofcom the power to take action against this kind of website. But Ofcom is still consulting on how the Act will be implemented and enforcement action won't happen for many months.

That's too long for the families of those who've lost lives because of people like Leonid Zakutenko.

-bbc