The terrorist group equally vowed to keep Leah Sharibu, the remaining Dapchi schoolgirl, as "a slave for life", the paper said.
He commiserated with the family of the aid worker, and said the Federal Government did all within its powers to save her life.
Liman and two other Nigerian aid workers, Alice Loksha and Saifura Hussaini Ahmed Khorsa, were working in Rann when they were kidnapped by ISWA in March.
Over the years, the armed group has kidnapped thousands of adults and children.
All three women were health workers tending to the humanitarian needs of displaced persons fleeing the insurgency in a restive Northeast region of Nigeria.
Islamic State-linked extremists in Nigeria have killed another abducted health worker despite an urgent plea from the International Committee of the Red Cross (ICRS) to spare her life, Nigeria's government said late Monday. It claimed both women were apostates because they worked for the Red Cross and Unicef.
Also to be enslaved is the remaining aid worker, Ms Alice Ngaddah, a Christian who works with Unicef.
In the audio sent to one of her male friends when she was captured in March, Leman, who spoke in Hausa, said her parents should be informed that she had been kidnapped.
"We are deeply disturbed, the whole family is disturbed", he said in Hausa, in an interview in the Borno state capital, Maiduguri. They are shooting everywhere please pray for me; please go and tell my parents that I am in trouble.
"We are concerned that many people in the region will not have access to medical support if the region becomes too unsafe for staff to operate", Aleksandra Mosimann, a spokeswoman for the ICRC, told the New York Times. That was the last that was heard from her.
However, in a statement issued in London on Monday, the Minister of Information and Culture, Lai Mohammed, described the killing as dastardly, inhuman and ungodly, saying nothing can justify the shedding of the blood of innocent people.
"President Buhari appealed to the ICRC to continue their services in Nigeria, and not give up, despite the unfortunate and painful loss of their staff", the statement said.
"We hereby, call on the Federal Government to expedite and prioritise the safe return of all civilians abducted by insurgents and emphasise that the government exhibit a greater sense of responsibility by ensuring the safety and security of citizens and fulfil its promise of ending the security challenges in the country".