The prosecutor general summoned Salman from prison, where he is serving a sentence for inciting disobedience, for questioning about “violations” posted on his Twitter account, the official BNA news agency reported on Sunday.

It later said that Salman denied any wrongdoing and that the prosecutor decided not to press charges and ordered him returned to prison to serve the rest of his sentence.

The prosecution also ordered an investigation into who was behind the tweets which, according to BNA, “incited” against the government and called for demonstrations, AFP reported.

Salman’s Al-Wefaq bloc earlier denounced the summoning of its chief by the prosecution, saying it “violates the Bahraini constitution and national law, as well as international covenants related to freedom of opinion and expression”.

The opposition chief was sentenced on June 16 to four years in jail after being convicted of inciting disobedience and hatred.

An appeals court is reviewing that conviction, but the prosecution is demanding the annulment of his acquittal on the more serious charge of plotting to overthrow the regime and seeking a tougher sentence.

A ruling on the appeal is expected on March 30.

Al-Wefaq renewed earlier calls for its leader to be released “immediately”.