WASHED up on a rocky outcrop, this is the latest example of the $2.5 million fleet of lifeboats that Australian taxpayers have paid for to tow asylum seekers back to Indonesia.

The bright orange vessel washed ashore on Tuesday on Agropeni beach near Kebumen on the southern shore of Central Java.

Twenty-six asylum seekers were on board the lifeboat, which ended up on the rocks after the passengers had already been transferred to shore. They had their details taken by local officials but were not detained.

Indonesian police have taken control of the lifeboat although it is not clear where it will end up.

The conditions inside are basic, with a steering wheel, the odd seatbelt and a small diesel engine all visible inside a bare, riveted interior.

The pictures emerged as the Federal Government revealed it had spent $2.5 million on an unknown number of such “unsinkable” lifeboats to send asylum seekers back to Indonesia.

The head of Customs Mike Pezzullo told a Senate hearing in Canberra on Tuesday it was possible more would be bought.

“We’ll purchase as many as are required to successfully execute the mission that has been given to us by the government,” he said.

It remains uncertain what happens to the lifeboats after they reach Indonesia and in a Yes Minister moment, Mr Pezzullo denied the vessels were “disposable”, arguing they were rather “consumable”.

“They’re not assets that are required to be counted as assets in the inventory of the Commonwealth,” he said.

He refused to say how many had been bought to date, which suggests the second-hand vessels will not be handed back to Australia by Indonesian authorities.

“That would give our adversaries and idea of our capacity,” he said.

News Corp understands that the number is 12.

Mr Pezzullo did reveal that the lifeboats were equipped with a radio, basic navigation equipment, lights and radar reflectors — all for about $200,000 each.

The commander of Operation Sovereign Borders Lieutenant General Angus Campbell refused to tell the Senate anything about the lifeboat issue.

“It’s an operational on water matter,” he said.

Labor’s defence spokesman Stephen Conroy, who invoked several Hollywood movie scenarios during questioning, caused an uproar when he accused General Campbell of being engaged in a political cover-up.

The general said that he took “extreme offence” at the suggestion.

Since the tow back policy began on December 19 last year no boats have arrived on Australian soil and about six have been towed back to Indonesian waters prompting numerous incursions by Australian Navy and Customs vessels into Indonesian sovereign waters.

Mr Pezzullo said no Navy or Customs officers would be “hung out to dry’’ over the half dozen incursions into Indonesian waters. He refused to answer whether or not the vessels were ordered to “cross the line”.

It was also revealed that $20 million of taxpayer funds has been spent on anti-people smuggling material during the past three years. Some $7.4 million has been invested so far this financial year.