Israeli police recommended bringing criminal charges against Prime Minister Benjamin Netanyahu's wife on suspicion of misuse of state funds and inflated household spending, Israeli media have said.

Police said in a statement on Sunday that they had concluded an investigation and had presented their findings to prosecutors, who would decide what action to take.

The statement offered few details but unsourced reports in all of Israel's main media outlets said police had recommended that charges be brought.

The suspicions relate to Sara Netanyahu's alleged misuse of state funds to pay a care-giver for her ailing father before his death; the hiring of an electrician who did not meet the requirements of a government tender; and for opulent meals.

READ MORE: Netanyahu's wife probed over alleged state funds misuse

The prime minister denied the allegations in a Facebook post. "In the police statement there was no recommendation to bring Mrs Netanyahu to trial. In contrast to reports, Mrs Netanyahu did not commit any crime."

The investigation was prompted by a government auditor's findings and by information provided by a former chief custodian at the official residence. In February, he won damages for emotional distress after a labour court found that Mrs Netanyahu had repeatedly scolded him and other household staff.

In a separate report by the state auditor on Tuesday, the prime minister was criticised over free air tickets that he and his family received for travel abroad when he was finance minister more than a decade ago.

No criminal charges have been brought in that investigation. Netanyahu's lawyers said he had broken no laws in having travel and expenses covered by organisations that invited him to speak at events raising funds for Israel, or by private individuals associated with those groups.

Opulent lifestyle

The Netanyahus have long faced scrutiny over their spending and accusations that their lifestyles are out of touch with regular Israelis.

The Israeli first lady has come under fire for her expensive tastes and alleged abusive behaviour toward staff.

The Netanyahus say they are the victims of a media witch-hunt and have denied any wrongdoing.

The prime minister says political opponents cynically target his wife as a way to get even with him.