* Netanyahu to be questioned over gifts from businessmen
* Prime minister's office denies any wrongdoing
* Attorney general approved criminal investigation
By Luke Baker
JERUSALEM, Jan 2 (Reuters) - Police are expected to question Prime Minister Benjamin Netanyahu at his official residence in Jerusalem on Monday on suspicion of receiving gifts from businessmen in breach of his role as a public servant, Israeli media reported.
The move was authorised by Attorney-General Avichai Mandelblit, who decided after a preliminary probe that there was sufficient evidence for a criminal investigation, Haaretz newspaper reported. The questioning will take place on Monday evening, Israel Radio said.
The police and Justice Ministry would not confirm when the interview would take place or the nature of the investigation, details of which have appeared in the media in recent days. Netanyahu's office has denied any wrongdoing.
"All the supposed affairs will turn out to be fiction," his family spokesman said on Monday. "We are repeating: there will be nothing, because there is nothing."
Photographers were camped outside the heavily guarded residence, hoping to get pictures of investigators arriving. Black screens were erected inside the gates of the property to block the view.
Haaretz and other newspapers said the probe related to gifts worth "hundreds of thousands of shekels" ($1=3.85 shekels) given to Netanyahu by Israeli and foreign businessmen.
Channel 2, a commercial network, said the investigation was one of two cases now open against the prime minister, although it said details of the second remained unclear.
Netanyahu, 67, has been in power on and off since 1996. He is currently in his fourth term as prime minister and will become Israel's longest-serving leader if he stays in office until the end of next year.
He and his wife, Sara, have weathered several scandals over the years, including investigations into the misuse of state funds and an audit of the family's spending on everything from laundry to ice cream. They have denied any wrongdoing.
Netanyahu is not the first prime minister to be questioned in a criminal case.
Ehud Olmert, who held office from 2006 to 2009, is currently serving 18 months in prison after being convicted of breach of trust and bribery in 2014.
Former prime minister Ariel Sharon was questioned while in office in 2003 and 2004 over allegations of bribery and corruption involving him and his two sons. In 2006, his son Omri was convicted of corruption and served time in prison.
Netanyahu's police appointment drew a barrage of commentary from the centre-left opposition in parliament, with politicians calling for him to go.
Ahead of a cabinet meeting on Sunday, Netanyahu responded, saying: "I suggest the opposition calm down."
Israeli commentators pointed out that while Netanyahu may be questioned, it has happened many times in the past and prime ministers have gone on governing, sometimes for years. (Editing by Mark Trevelyan)