Lebanon's President Michel Aoun has come under fire after it emerged that tea donated by Sri Lanka for victims of the Beirut blast was distributed instead to families of his presidential guards.

Critics see it as yet another example of official corruption in a country reeling from the August 4 explosion that killed more than 190 people, wounded thousands and ravaged central Beirut.

Sri Lanka, many of whose expat community in Lebanon work as housemaids, was one of several nations that rushed to show support in the wake of Lebanon's worst peace-time disaster.

The president's office on August 24 released a picture of Aoun receiving the Sri Lankan ambassador, and quoted her as saying Colombo had "donated 1,675 kilos (3,685 pounds) of Ceylon tea to those affected by the Beirut blast".

After Lebanese media and social media asked what happened to the donation, it issued a second statement on Tuesday.

The presidency said Aoun had written to his Sri Lankan counterpart to thank him for "a gift of Ceylon tea that had been received by the army... and distributed to the families of soldiers in the presidential guard".

Social media erupted in criticism, with the hashtags "tea thief" and "Ceylon tea" trending on Twitter.

"The tea was sent to the Lebanese, particularly those affected by the explosion. Of course it wasn't a present for those who don't need it," wrote Paula Yacoubian, a former MP who resigned after the blast many blame on official neglect.

"Distributing the aid to your entourage is shameful," she wrote.

Another user quipped: "The excuse that it was a present for the president is even worse than the sin itself."

Beside the tea controversy, social media users have also been up in arms over the fate of 12 tonnes of fish that Mauritania sent in mid-August.

After widespread calls to know its whereabouts, the army said Monday it had received the fish and "stored it according to public safety standards".

It was talking to several associations preparing meals for those in need "to cook it and distribute it to those affected by the port blast".

On Twitter, yet another user made light of the food aid controversy.

"The presidential palace, or the palace of the people, invites you to a free lunch on Sunday," she wrote.

"Open buffet on Mauritanian fish, and open bar on Ceylon tea."