Australian firms have secured contracts to supply military equipment to Saudi Arabia, an autocracy accused of ongoing war crimes in a conflict that has killed more than 10,000 yemeni civilians.

Defence has approved four military exports to the kingdom in the past year and the Australian government has led the push for more.

But the government is refusing to release details of the approved military sales, citing commercial-in-confidence rules.

Defence Industry Minister Christopher Pyne visited Riyadh in December to promote Australian materiel to senior government figures including Prince Mutaib bin Abdullah bin Abdulaziz al Saud, the head of the National Guard.

"The minister received a very positive reception, as did the business representatives who visited," a spokeswoman for Mr Pyne said.

The pitch to sell more to the world's biggest buyer of arms comes after the Dutch parliament voted last year to ban military exports to Saudi Arabia on humanitarian grounds.

Since March 2015, Saudi Arabia has led a coalition of Arab states on a bombing campaign in Yemen's north against Houthis.

The United Nations recently confirmed at least 10,000 Yemenis had been killed in the conflict and warned some coalition attacks "may amount to war crimes".

A coalition blockade has pushed Yemen to the brink of famine.

"I despair for Yemen", said Sarah Phillips, a University of Sydney researcher.

Dr Phillips said both sides had used brutal tactics but Saudi Arabia's airstrike targeting had been "reckless at best", hitting funerals and hospitals at times.

Asked about Australian military exports to Saudi Arabia, Dr Phillips said: "I would find that deeply concerning, with the ways in which previous assistance from other Western nations has been used upon the civilian population."

The US provides logistical support and refuelling for the coalition but former president Barack Obama halted the sale of a precision-guided technology to the Saudis on humanitarian grounds. President Donald Trump reversed the decision this month.

Meanwhile, the legality of Britain's sales is being challenged in a High Court case and the Ministry of Defence is investigating 257 alleged breaches of international law by Saudi Arabia in Yemen.

Saudi Arabia briefly appeared on a UN "list of shame" as a violator of the rights of children in war but surprisingly was then "temporarily" removed.

Greens Defence spokesman Scott Ludlam said an Australian minister soliciting military contracts from Saudi Arabia was "hideous".

"They are bombing hospitals, schools, agricultural areas, the port, bridges, power infrastructure, water infrastructure, attempting to starve an entire country into submission," Mr Ludlam said. "These are the sorts of crimes arms embargoes are for."

Australia has called for a ceasefire but neither Mr Pyne nor Foreign Minister Julie Bishop would comment on Saudi Arabia's use of force.

Mr Pyne said military export applications were subject to "strict controls" and assessed against five criteria: international obligations, national security, human rights, regional security and foreign policy.

Mr Pyne would not comment on the value of materiel exports to Saudi Arabia or say whether the market was growing. He declined to name which businesses accompanied him to Riyadh.

The shipbuilder Austal told Fairfax Media it joined the trip and had held preliminary talks about providing Saudi Arabia with high-speed support vessels. Thales Australia would not comment on whether it attended or exports to the country.

Lowy Institute research fellow Rodger Shanahan said if Australia were to expand exports to Saudi Arabia, it should focus on defensive equipment rather than munitions that could be misused.

"As the British have found out, Saudi use of overseas munitions in a military operation you might not want your name attached to is always a potential problem," Dr Shanahan said.

Saudi Arabia first denied then admitted to using cluster bombs purchased from Britain in the 1980s.