Gunmen stopped an ambulance carrying two wounded soldiers south of the provincial capital of Al-Arish, the sources said.
The gunmen shot and wounded the paramedic and took the ambulance and one of the soldiers, the sources said.
The body of the abducted soldier was later found about 30km down the road near Sheikh Zuweid, they added.
Authorities this week executed six members of Sinai Province, the country’s most active militant group.
Sinai Province changed its name from Ansar Bayt al-Maqdis after pledging allegiance to ISIS, the ultra-hardline Sunni group that has seized large parts of Iraq and Syria.
Separately, two women were earlier killed when a stray shell fell on their home in Sheikh Zuweid, the security sources said.