Germany's government has left the door open to exporting arms to Saudi Arabia and its allies in the Yemen conflict, the news weekly Der Spiegel reported Wednesday, seemingly in spite of a deal within the country's ruling coalition.

There would be no German arms embargo on countries taking part in the Yemen conflict, which has left 10,000 people dead since 2015, the news weekly said on its website. It cited a letter to that effect sent by the economy ministry to Social Democratic Party (SPD) MP Thomas Hitschler.

But part of a March coalition deal between Chancellor Angela Merkel's conservative CSU party and the centre-left SPD appeared to rule out arms exports to countries "directly involved" in the conflict.

The letter to Hitschler, however, said that export licences will be granted on a case by case basis, Der Spiegel reported.

The issue provoked a sharp dispute within the SPD's parliamentary group, the news weekly said, with several deputies accusing Foreign Minister Heiko Maas -- himself a SDP member -- of kowtowing to the Saudis.

Merkel's coalition is already fragile, with its third member, the Bavarian conservative CSU, agitating for a migration crackdown as well as facing regional polls on Sunday.

The Der Spiegel report also comes amid mounting international scrutiny of the disappearance of Saudi journalist Jamal Khashoggi, last seen by his fiancee entering the Saudi consulate in Istanbul last week.

Turkish police say they think he was killed by a 15-strong team sent to Istanbul, an accusation strongly denied by the Saudis.

The authorities in Turkey have released security camera footage showing a man thought to be Khashoggi entering the consulate.

Germany and Saudi Arabia only returned their ambassadors in September after 10 months of frosty relations following criticism from Berlin of what it said was Saudi interference in Lebanese affairs.

Saudi Arabia leads a coalition that intervened in Yemen in 2015 to support the government there against armed rebels backed by Iran.

Thousands have since died -- mainly civilians -- in what the UN has labelled the world's worst humanitarian crisis.