Susta (Bihar), Aug 5 - The presence of illegal settlers is threatening wildlife in the Susta region of the Valmiki Tiger Reserve as forest staff don't patrol the area because of a territorial dispute between India and Nepal, say officials and conservationists.

'The (Susta) area is actively used by criminals for timber and cane smuggling; wildlife poaching takes place across the Madanpur range. Nationals of both India and Nepal are involved in the crimes,' said Samir Kumar Sinha, assistant manager of the NGO Wildlife Trust of India (WTI).

He said at least two tigers have been killed in the Valmiki reserve in the recent past. One of the tigers was killed in May last year close to Susta, which is in West Champaran district. This area is 300 km from Patna.

Sinha says the area has been a soft target for wildlife poachers and the situation could get worse if the dispute with Nepal is not sorted out soon.

The dispute relates to the altered boundary between India and Nepal owing to the Gandak river changing its course.

In 1816, as part of the Sugauli Treaty between then British India and Nepal, it was decided that the eastern side of the Gandak river would be in India and the western side in Nepal.

Since then the river, called Narayani in Nepal, has changed its course several times. As a result the Susta area that was once part of Nepal is now in India.

An Indian official requesting anonymity told IANS: 'Although Nepal claims Susta is its territory as per the 1816 Treaty, India proposes the present course of the Gandak should be the determining factor.'

The Valmiki Tiger Reserve, which covers Susta, was created in 1978 when the dispute was already on.

Today poachers are taking advantage of the continuing dispute.