SINN Féin has selected Daithí McKay's predecessor at Stormont to replace the former North Antrim MLA following his resignation last week.
In a highly unusual move, Philip McGuigan will return to the assembly, having previously served as a Sinn Féin MLA a decade ago.
South Derry-born Mr McGuigan, who is in his mid-40s, represented North Antrim at Stormont from 2003-2007.
Eyebrows were raised when Mr McKay was selected to contest the 2007 assembly elections ahead of the incumbent, who was an accomplished Gaelic footballer. Father-of-four Mr McGuigan is currently a Sinn Féin representative on Causeway Coast and Glens Council.
Mr McKay resigned last week hours after The Irish News revealed his backchannel dealings with loyalist blogger Jamie Bryson.
The former chairman of the assembly's finance committee, who was regarded as one of his party's most promising MLAs, exchanged secret messages with Mr Bryson ahead of last September's committee hearing into the sale of Nama's Project Eagle loan portfolio.
The messages revealed that Mr McKay coached the loyalist over when to allege that the then First Minister Peter Robinson was set to benefit financially from the £1 billion-plus deal. The former DUP leader denies the allegation.
Deputy First Minister Martin McGuinness described the former MLA's actions as "profoundly disturbing".
The messages also made reference to Stormont Finance Minister Máirtín Ó Muilleoir, who was a member of the finance committee at the time and was involved in questioning Mr Bryson.
Stormont's other main parties have called for Mr Ó Muilleoir to step down while the assembly's standards commissioner conducts an investigation into the matter.
The South Belfast MLA has so far resisted the calls and insists he has done nothing wrong.
The Irish News reported on Wednesday the possibility that in addition to Mr McKay and Sinn Féin worker Thomas O'Hara communicating with Mr Bryson, a third person was involved in the backchannel.
The speculation was fuelled by a message from Mr O'Hara asking the loyalist to send documents to the email address hutcheontom@hotmail.com.
It now appears possible that the email address belongs to Mr O'Hara and that 'hutcheontom' is a corruption of 'hunshin Tom', a reference to the townland of Lisnahunshin near Portglenone that the Sinn Féin worker hails from.
Announcing Mr McGuigan's co-option, Sinn Féin's Carál Ní Chuilín said the Queen's graduate had been selected following consultation with Sinn Féin activists in the constituency.
"Philip is an excellent public representative and has served as a councillor in the area since 2001 and was an MLA for North Antrim from 2003 to 2007," she said.
"I have no doubt that with Philip's return to the assembly will continue to provide first class representation to the people of North Antrim."
Mr McGuigan was far from the bookies' favourite to succeed Mr McKay. Schoolteacher Patrice Hardy and fellow councillor Cara McShane had both been tipped to be the former finance committee chairman's successor.
SINN Fein is to co-opt senior party activist Philip McGuigan into its North Antrim seat at Stormont.
