The Israeli State Comptroller is investigating the sharp rise in the taxpayer-funded expenses of Prime Minister Benjamin Netanyahu and his family.

The investigation was prompted by the emergence of new details on the costs of maintaining the Prime Minister’s family.

A lengthy freedom of information campaign — which was led by an individual student — yielded the entire expense budget for the Prime Minister’s personal needs.

This revealed that more than half-a-million shekels (nearly £100,000) had been spent on providing a bed for Mr Netanyahu’s use on the plane that flew him to Baroness Thatcher’s funeral, which took place in London last month.

According to the figures published this week, in 2012 the government paid 5.4 million shekels (just under £1 million) for the maintenance of the official Jerusalem residence used by Mr Netanyahu and his family and their two private homes in Jerusalem and Caesarea.

The sum included a variety of items such as hospitality, clothing and cosmetics. It was 80 per cent more than the Prime Minister’s personal budget in 2009 and more than double that of any of Israel’s other recent prime ministers, Ehud Olmert, Ariel Sharon and Ehud Barak.

The revelations prompted the State Comptroller — former judge, Yossef Shapira — to begin a series of consultations on regulating prime minister’s expenses, which could potentially lead to an official investigation over whether Mr Netanyahu misused public funds for his personal needs.

The Prime Minister’s Office, which initially tried to block the publication of the figures, has given a range of responses to the reports.

In relation to the bed that was fitted in the aircraft to London, his office initially responded that the expense was justified as the Prime Minister needed to arrive refreshed for his meetings with David Cameron and the Prime Minister of Canada, Stephen Harper, taking place after Baroness Thatcher’s funeral.

Explaining the other, personal expenses, the PM’s office said that “the figures include the cost of hosting official events in the prime minister’s residence and the cost of the many official meetings that are held there.”

Since the release of the figures, allies of the Netanyahu family gave interviews in which they talked about the family’s “frugal” lifestyle.

The high costs of maintaining the residence, they argued, were incurred as a result of the Prime Minister working late into the night and constantly holding meetings there.