The man was taken captive when armed robbers attacked a constuction company in Ogoni hoping to find the payroll on the premises, an oil industry source said.
A police source in the Rivers state capital Port Harcourt said they had almost no details of the night-time abduction and could not confirm the report.
The source said that the robbers killed one Nigerian policeman as they made their escape. They apparently seized the Italian in the hope he would lead them to the company's money.
Abductions of foreigners are common in the Niger Delta, home to Africa's biggest oil industry, but they are usually connected either to militant attacks on oil facilities or to demands for ransoms.
British detectives have also arrived in Lagos to help police investigate the assassination on Satuday of Funso Williams, a leading candidate for governor of Lagos.
Nigerian police have arrested a senator in connection to the murder of Williams, who was found strangled in his study on Thursday.
"Nine people have been arrested. They are four policemen who were assigned to (Williams') security, two civilian guards, one housemaid, a politician and his campaign manager," said police spokesman Haz Iwendi.
He named the politician as Senator Seye Ogunlewe, a member of the ruling People's Democratic Party (PDP), like Williams.
"He is also an aspiring PDP gubernatorial candidate," said Iwendi, adding that the nine were being questioned in Lagos.
The upsurge in violence of assasinations, inter-ethnic killings and clashes between paid thugs armed by rivial politicians is increasing in the run-up to elections in 2007.
Analysts blame political violence partly on a lack of internal democracy in Nigeria's political parties, arguing there are few legitimate avenues for members to rise to prominence.