The senate president, Bukola Saraki, has condemned the killing of Saifura Khorsa, a health worker from the International Committee of the Red Cross (ICRC), by Boko Haram terrorists.
Saifura was kidnapped about six months ago at the Rann camp for internally displaced persons by the terrorists.
The murder of the 25-year-old midwife came barely a month after Boko Haram released photos and audio recording of Ms Khorsa and two other female aid workers begging the Nigerian government to quickly come to their rescue as their time of being safe in custody of the insurgents was running out.
The other two still in Boko Haram custody are Hauwa Liman and Alice Loksha.
President Muhammadu Buhari and other international organisations have condemned the act, describing it as heinous.
In a statement by his special adviser on media & publicity, Yusuph Olaniyonu, Mr Saraki said the killing of the aid worker represents a new low by Boko Haram insurgents.
"Such horrific actions have no place in Nigeria. I join all Nigerians and the international community in condemning this killing in the strongest possible terms.
"The killing of aid workers, who choose to go into troubled spots, both in Nigeria and around the world, represents a new low by the insurgents, as humanitarian workers are some of the most courageous and selfless people on the planet," he said.
He also called on the military to ensure that the other two Red Cross workers and Leah Sharibu, who are still in Boko Haram's captivity, are released.
Miss Sharibu is one of the over 100 schoolgirls kidnapped by the Boko Haram in Dapchi, Yobe State, earlier in the year.
While all her other schoolmates who survived the kidnap have been released by the terrorists, Miss Sharibu was held back by the Boko Haram for allegedly refusing to denounce her Christian faith.
Nigerians as well as local and international rights groups have appealed for Miss Sharibu's release and called on the federal government to do all possible to ensure her release.
"Additionally, the continued abduction of the late Saifura's ICRC colleagues, Hauwa and Alice, by the militants, alongside the captivity of the young Dapchi schoolgirl, Leah Sharibu, must end.
"I call on our brave servicemen and women on the frontlines to do all that they can to protect the rescue workers on the ground and employ every God-given resource that is available to us to rescue Leah Sharibu and the ICRC humanitarian workers," Mr Saraki said.
While extending his condolences to the family and loved ones of the deceased, the senate president said he will continue to support the government to ensure that peace and security are restored in the North-east.
The Monday murder of the 25 years old midwife may have been a sign of the terrorists' new stance on how it may handle abductees in its custody should government fail to hearken to its call for a negotiated release of the captives.