A Senegalese singer was formally charged with "offending the head of state and broadcasting fake news", her lawyer told AFP Wednesday, after audio of her lashing out at President Macky Sall went viral.

Amy Colle Dieng, 39, was arrested on August 3 after unleashing a social media storm with a recording shared via the WhatsApp messaging service and then uploaded to YouTube.

"She was charged on Tuesday night," and will be kept in detention until her trial, said her lawyer Boubacar Barro.

A separate source said a second person who administrated the WhatsApp group concerned had also been charged.

If convicted, they risk prison sentences of up to three years on the charge of distributing fake news, and up to two years for offending a head of state.

In the recording, Dieng calls President Sall a "sai sai", or "scoundrel" in the local Wolof language, who "operates in the shadows" to achieve his aims.

She is also heard saying that the president, elected in 2012, had done "nothing" for the country and "stole" a victory in recent legislative elections.

Dieng is also heard declaring her support for ex-president Abdoulaye Wade, who stood as an opposition candidate in the elections, and she criticises administrative errors that marred the vote.

The case has caused a sensation and led the country's top prosecutor to vow that Senegal would stamp out "abusive" online behaviour.

Dieng's case comes after four people were charged in June with "offending public morals" for distributing a fake image of Sall naked, also via WhatsApp.

Another of Dieng's lawyers, Cire Cledor Ly, described her detention as "arbitrary" to AFP, and has said the crime of offending a head of state had "no place in a democratic society".

Source: AFP