The police claimed to have solved two murder cases in the district with the arrest of five persons here on Thursday.
The accused include a woman, one youth from Kerala, two persons from East Champaran district in Bihar and a 52-year-old man from Tirupur.
Superintendent of Police A Arun told reporters here that R. Thirumoorthy (52), A Fatima (27) and V. Rajesh (27) were arrested for killing Thirumoorthy's brother Nagaraj (42), who was running textile unit in Tirupur city, by mixing cyanide in the drink.
The killing of Nagaraj came to light after his wife lodged a complaint on April 17 that her husband was missing. A few days later, the body was traced from Kodaikanal.
Mr. Arun said that Thirumoorthy had a strained relationship with his brother and hence, used his friendship with Fatima to plot the killing.
The duo sought the help of Rajesh to procure cyanide from a goldsmith.
After killing Nagaraj, the accused disposed of the body at Kodaikanal to mislead the investigation agencies.
Mr. Arun said that Dharmendra Giri (28) and Ram Babu (32), both hailing from Motihari in East Champaran district of Bihar, murdered K. Neminathan (50) at Kangayam on March 7 owing to personal enmity.
The accused used a broken bottle to stab Neminathan to death.
Two Nigerians held
Tirupur North police arrested two Nigerian nationals on Thursday for staying in the city without any visa and other travel documents.
Police said that Anoze Clement Chinuzov (30) and Igwebueze Ifanji Livinus (32) were picked up from near the Railway Station. by Inspector while they were roaming aimlessly.
On questioning, it was found that the two were not in possession of necessary documents needed for international travel.
Police officials said the duo had told the investigation agencies that they had come down to the city from Bangalore on June 16 for selecting garments for export to their native city of Lagos in Nigeria.
They were remanded to judicial custody under Section 3 (2) ( c) r/w 14 of Foreigners Act, 1946.
Mr. Arun said 19 Nigerians had been detained in the last seven months.