Surendra Singh, a BJP worker, was shot at his home at around 3 am on May 25.

The main accused in the murder of a former village head in Uttar Pradesh's Amethi, who worked closely with BJP leader Smriti Irani during her Lok Sabha campaign, was arrested by the police today, news agency IANS reported.

Wasim was arrested by the police after an encounter in the Jamo police station area, police said. He sustained a bullet injury on his leg during the gunfight and was being treated in Jamo CHC hospital, they added.

Security forces were stationed at the hospital and no one was allowed to meet him, Assistant Superintendent of Police Daya Ram was quoted by IANS as saying.

"All the five accused in the murder of Surendra Singh have been arrested. Four have been sent to jail," he said, adding that Singh was killed because of a personal rivalry. Ramchandra, Dharmanath and Naseem were arrested on Monday.

Surendra Singh, a BJP worker, was attacked at his home at around 3 am on May 25; he died later at a hospital in Lucknow where he was taken for treatment, the police said.

Smriti Irani had rushed to Amethi to attend his funeral. She had said she will "move the Supreme Court, if needed, to seek death sentence" for the killers.

Ms Irani had been a regular visitor to Amethi ahead of the elections. Surendra Singh had actively participated in her election campaign and had earned praise from the BJP leader in her speeches at public meetings.

Smriti Irani defeated Rahul Gandhi by over 55,000 votes in the constituency that he had been winning since 2004. The loss of Amethi had pushed the Congress's tally in Uttar Pradesh to a single seat.