Dinko Valev, 29, uses two armoured vehicles to patrol territory near the city of Yambol, close to the border with Turkey.

But now it has been revealed that the Bulgarian State Agency for National Security have warned him he is being targeted by the terrorists.

The agent said he was on a list of names for which ISIS was offering a bounty with payment being made once a video or picture confirming the deed had been provided.

The information about the ISIS offer was found on several Islamist websites which are reportedly funded by terrorist organisations.

Valev was described as the ‘leader of a paramilitary unit operating on the Bulgarian-Turkish border along with a dozen other men’.

It is thought ISIS targeted Valev because it was keen to be seen as a champion of migrants from the Middle East, especially Muslims, and is hoping to recruit some refugees for terrorist operations in Europe.

But Valev appears undeterred by the threat, and even posted a media report about it on his website.

Earlier this year Valev said he regarded every illegal migrant as a jihadist and dismissed claims he was terrorising his captives.

He said: ‘I would describe it as simply a sporting activity.
You can’t describe sportsmen as violent.’

In March Valev says people have been turning up with off-road trial bikes and dogs to help in the search for illegal immigrants.

Others, including himself, also set off on their hunts on horses.
When captured, the immigrants are then handed over to police, he said.

But the Helsinki Committee for Human Rights have demanded officials clamp down on the immigrant roundups being organised by Valev, saying what he is doing is illegal and branding him a criminal.