Morocco has recalled its ambassador after the Algerian foreign minister accused the kingdom's banks of "laundering hashish money" in Africa, in the latest diplomatic spat between the North African rivals.
The foreign ministry said it also summoned Algeria's charge d'affaires in Rabat on Friday evening to protest the "very serious statements... concerning the African policy of the kingdom of Morocco."
Algerian Foreign Minister Abdelkader Messahel made his comments at a meeting of business leaders in Algiers on Friday, excerpts of which were widely circulated on social media.
He was discussing the sharp increase in investment by Moroccan banks in sub-Saharan Africa in recent years and their competition with Algerian lenders.
"Everybody knows that the Moroccan banks launder hashish money. The leaders of many African countries have told me this," Messahel said.
He went on to suggest that Royal Air Maroc, the kingdom's flag carrier, transported "more than just passengers."
The Moroccan foreign ministry said Messahel's comments displayed a "level of irresponsibility unprecedented in the history of bilateral relations."
They "testify to a deep and inexplicable ignorance of the basic workings of the banking system and civil aviation," it added.
The North African neighbours have been at loggerheads for decades over the Western Sahara, a territory disputed between Morocco and Algeria-backed independence movement, the Polisario Front.
They have frequent diplomatic rows and their land border has been closed since 1994.
Northern Morocco is a key producer of hashish for export to Europe.
While Moroccan law bans the sale and consumption of the drug, that has not stopped farmers growing vast plantations of it, providing a living for some 90,000 households, according to official figures for 2013, the most recent available.
Smoking hashish is seen as part of local culture, and is largely tolerated by the authorities.