The police stumbled across a document forgery racket while investigating a complaint against use of a fake document to settle a civil dispute between siblings.

Jameela of Pallithazhath had lodged a complaint that her brother Khader, 48, produced a fake document to prove that he had bought the land owned by her. He had reportedly produced an agreement printed on a pre-dated stamp paper to prove his claim.

Investigations led by Muvattupuzha sub-inspector P.S. Shiju threw open a racket involved in selling stamp papers with older dates and manipulating seals used on them. Following the lead, the police team arrested Ravi, 62, of Palakkad, who has been identified as the kingpin, and three others believed to be his accomplices — Santhosh, 40, of Kuruppampady; Hassainar, 58, of Vengola; and Kamal, of Perumbavoor. Sanil, 28, son of Khader, was also arrested in this case.

The police team seized more than 100 stamp papers, some of them even dated to 1995, from the office of Santhosh at Perumbavoor police station road. Police said that Hassainar and Kamal would canvas clients and bring them to Santhosh, who used the stamp paper produced by Ravi, suspected to be sourced from various stamp paper vendors.

The accused used to charge nearly 10 times extra for old stamp papers, which were mostly used to manipulate civil disputes, police said.

Preliminary investigations reportedly show that the accused used such documents to settle land deals worth lakhs of rupees. The main accused, Ravi, has been found to have used fake seals of vendors from different districts and sub-treasuries, police said.

The Muvattupuzha police will seek custody of Ravi on Tuesday to probe whether any stamp vendors or treasury officials connived with him.

The accused sold pre-dated stamp papers for land deals, police say.