A nine-inch-long knife which is alleged to have been used by naval officer M L Jerome Mathew in killing television executive Neeraj Grover in Kannada actress Maraya Monica Susayraj's flat was recovered from the home, police said.

"We have recovered the knife from a chute situated near the bathroom of Susayraj's flat in Malad," Joint Commissioner of Police (Crime) Rakesh Maria said Monday.

Mathew is suspected to have washed the weapon and thrown it in the chute after the murder when Susayraj had gone to a nearby mall for fetching some bags which were used in disposing off the body, Maria said.

Grover, a creative head with TV production house Synergy Adlabs [Get Quote], was stabbed to death allegedly by Mathew in suburban Malad on May 7 over a suspected "love triangle".

Susayraj and Mathew allegedly chopped Grover's body to several pieces, put the parts in three bags and then disposed it by burning it at Manor, on the outskirts of Mumbai.

Mathew was allegedly unhappy with Grover's proximity to Monica while Susayraj, aspiring to get into TV serials, was continuing with the friendship hoping to get a break, police said earlier.

Police earlier recovered the knife which was used by Mathew in cutting the body. "We have recovered both the weapons which will surely help us in the case," Maria said. Maria said the knife has been sent for forensic tests and experts are hopeful of finding some traces of blood on the knife.

The knife was found in the chute which is generally used for putting waste material and was hidden in plastic material. Mathew led a police team to the spot during interrogation which led to the discovery of the weapon, Maria said.

Mathew, who was arrested on May 21, initially did not tell interrogators where he had hidden the weapon while Susayraj did not know anything about it, Maria said.

Both Mathew and Susayraj have been remanded to police custody till June 3 by a local court and will be transferred to judicial custody when they are presented before a court on Tuesday.

Meanwhile, Maria said Grover's family based in Kanpur will be handed over remains of the body by mid-June.

A police team is currently in Kochi, where Mathew is based, to collect more evidence against him as to what he did between May 9 (when he returned from Mumbai) and May 20 (the date of his detention) as "subsequent conduct" of the accused after committing the crime is important, Maria said.