More skeletons appeared to be tumbling out of the cupboard of accused Mallika as three persons complained to police about their missing relatives whom they believe were also killed by her, Umesh, a police official investigating the case said.

He said Mallika, 43, is turning out to be a tough nut to crack as she was not forthcoming to reveal more even though she admitted to killing six by administering cyanide.

Deputy Commissioner of Police Sharat Chandra, however, said, "we have to ascertain whether these (three) missing cases were the handiwork of Mallika."

"As per her own admission, she committed the first murder in 1999 and the next five later. However, she appears to be willing to reveal only part of her criminal past," he said.

"We had asked the public to come forward and give us any information in case they had encountered her or were one of the targets of her criminal activities," he said.

"The accused has only revealed six murders and has not been forthcoming and cooperative in revealing more details, hence we might have to subject her to a narco analysis," Chandra said.