Chandigarh, May 31: A 22-year-old Punjab farmer allegedly committed suicide within a week of his marriage after discovering that his wife's mother was a Dalit, with police terming it the state's first such case in recent memory.

Manpreet Singh left behind a purported suicide note saying he had been unaware of his wife's caste background and the revelation last week forced him to take the drastic step. The incident on Sunday night in Sangrur district's Lehra village exposed the caste fault lines in rural Punjab and came at a time tension has gripped Uttar Pradesh's Saharanpur following weeks of clashes between the Dalits and upper caste Thakurs.

Manpreet was an upper caste Jat Sikh, the dominant group within the Sikh community. His purported suicide note said: "I am Manpreet Singh Brar. Matchmaker Gurtej Singh Baba found a match for my marriage. I am a Jat and my father-in-law is also a Jat but his wife is a Ramdasia. I was told that she and her daughter were also Jats. That is why I married her."

According to the police, Manpreet came to know about his wife's caste background during a visit to his in-laws' home last week.

"He returned on Sunday and was very glum. He left his wife at home and went to his farm. Till late that night, he did not return home. Next morning, his body was found on the farm. The post-mortem revealed he had consumed poison," said Jagbir Singh, the station house officer of Lehra police station.

Manpreet's family has told the police that the matchmaker had assured them the bride's family was a Jat Sikh. The Ramdasias were originally Hindu weavers who had converted and become Sikhs. They are one of Punjab's 39 recognised Scheduled Caste groups. The state has a 32 per cent Dalit population, one of the highest in the country.

In Manpreet's case, the police have started a case of abetment to suicide against the matchmaker. "The matter is under investigation. The suicide note points to the caste issue. We are exploring whether there could be any other motive," said officer Jagbir.

In Punjab's villages, clashes have been reported between the Dalits and upper castes over land, but police officers said they could not recall such a suicide over caste reasons in recent years.

In Saharanpur, Dalits have accused Thakurs of attacking them and burning their homes and farms.

Last year, four Dalit youths were flogged publicly by vigilantes in Gujarat's Una for skinning dead cows.