Sinn Fein MLA Daithí McKay has resigned as MLA for North Antrim.
His resignation was announced by the party’s chief whip Carál Ní Chuilín.
“Daithí McKay has resigned as MLA for North Antrim with immediate effect and has been suspended from Sinn Féin,” she said in statement.
“His letter of resignation has been submitted to the speaker’s office.”
Mr McKay resigned hours after a daily newspaper claimed he had been in contact with Jamie Bryson before he appeared at the Assembly’s Nama inquiry.
Deputy First Minister Martin McGuinness said Sinn Féin did not have any knowledge of any alleged contact with witnesses.
“The allegations surrounding North Antrim MLA Daithí McKay are profoundly disturbing,” he said.
“If the allegations of inappropriate contact prove to be true, then Daithí McKay needs to seriously consider his position as an MLA.
“I want to state categorically that I had absolutely no knowledge of this exchange or contact.
“And having spoken to all relevant personnel in the Assembly I am now entirely satisfied that Sinn Féin had no knowledge of any such contact.”